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    How to Use こそあど Words to Refer to Things You Can't See Enhance Your Japanese Experience by Understanding the Intricate Nuances of These Seemingly Simple Words

    こそあど言葉 (ko-so-a-do words) are a series of Japanese words that are used to refer to something. Whereas English sets of these words tend to come in pairs, like "this" and "that," each こそあど set is made up of three words plus a question word. For example, の (this…), の (that…), の (that … over there), and の (which…?).

    When referring to something you can physically see, you'll make a choice between using こ, そ, or あ based on the distance between you and the object. However, things get a little hazy if you're referring to something that's not in sight when you mention it.

    For example, imagine your friend just told you that someone spread a rumor about your brother. You know the rumor isn't true, so you say:

    • ああ、[の・の・の] うわさ うそだよ。
    • Oh, that rumor is not true.

    Your choice comes down to how close you feel you are to the thing you are referring to, conceptually.

    Now, a rumor is obviously something you cannot see. And in fact, here you can choose between の, の, and の to address that rumor. Your choice comes down to how close you feel you are to the thing you are referring to, conceptually. In other words, the choice is based on your feelings towards the rumor. So, you'll choose の if the rumor feels closer to you, の if the rumor feels farther from you, and の if the rumor feels distant from you, or from both you and your friend.

    As you can see, the same basic concept of distance still applies here. But what does it really mean when something is regarded as "close" to you, "far" from you, or "distant" from you, conceptually?

    If you don't have the answer to that, you are in the right place! This article will explain what it all means, while showcasing different examples along the way. Understanding how the こそあど system really works allows you to enjoy speaking and reading in Japanese even more than you do now. Without further ado, let's get the ball rolling!

    Prerequisites: This article assumes you already know hiragana and katakana. If you need to brush up, have a look at our Ultimate Hiragana Guide and Ultimate Katakana Guide. Although I tried my best to make this article understandable for all levels of Japanese learners, the main topic of the article is advanced uses of こそあど words. We recommend that you have a solid grounding in こそあど before you start reading this.

    The ABCs of the こそあど System

    the concept of kosoado

    While each set of こそあど words has unique meanings and functions, they all share the same basic concept. Since you're reading this article, you're probably familiar with the gist of こそあど words. Still, we'll start with this information anyway because it's a necessary foundation for understanding the more advanced uses of こそあど.

    As a refresher, here is how こそあど words work when we use them for a physical object that we can see:

    Words that begin with こ are used for things that are close to the speaker, or closer to the speaker than the listener.
    Words that begin with そ are used for things that are farther from the speaker and/or are closer to the listener.
    Words that begin with あ are used for things that are far from the speaker, and the listener if there is one.
    Words that begin with ど are used to ask a question.

    Let's take a look at an example to make all these guidelines feel more concrete. Imagine you are at a party where everyone's drinking out of red cups. While talking to you, your friend forgets where they put their cup and wonders which one is theirs.

    • あれ、どれが私のだっけ。
    • Oops, I wonder which one is mine.

    Here, they ask a question with a ど-word, どれ. You point to the nearest cup and say:

    • 私のはこれだよ。
    • Mine is this one.

    In this example, you refer to the cup with a こ-word, これ, because it's closer to you, the speaker. Then, you point to the cup that's in between you and your friend and ask:

    • それじゃないの?
    • Isn't that one yours?

    This time, you use a そ-word, それ, because it is farther from you, the speaker. You might have learned that a そ-word is used when things are close to the listener. However, it can also be used when something is simply a little farther from the speaker, and the speaker judges it to be out of their こ-territory. This is illustrated in the image above.

    Unfortunately, you figure out that it isn't your friend's cup, but you see another cup that might be. This one is kind of far from both you and your friend.

    • あ、あれは?
    • Ah, what about that one over there?

    Since you point to a place that's distant from the both of you, you use an あ-word, あれ.

    It's quite simple, right?

    As mentioned earlier, the fundamental concept of distance applies to all types of こそあど words. However, when referring to something you can't physically see, "distance" is on a more psychological level instead. Now, let's move on and see what that means and how it works.

    What Are Things You Can't Physically See?

    As we briefly described above, when you're referring to something that you can't physically see, the こそあ words you choose to use are based on your perspective. That is, how you regard the thing (or person) and what you consider to be its relation to you and the person you're addressing.

    But first and foremost, what exactly do we mean when we talk about "something that you can't physically see?" It obviously can't be a physical object in front of you, so it's either a physical object that is out of sight, or an abstract concept that is never visible, like the rumor in that first example.

    It's also something that has already been mentioned or implied by you or others earlier. 1 That something could be an abstract concept or a memory, but it's not limited to that. It could also be a thing that does physically exist, but is not within sight.

    For example, let's say you watch a TV show featuring a ramen shop. The next day, you tell your friend about the shop.

    • 昨日、テレビでラーメン屋が特集されたんだけど、その店すごく 美味おいしそうだったんだ。
    • Yesterday, I watched a TV show featuring a ramen restaurant and the restaurant looked really good.

    In this case, the ramen shop is an actual place, but you aren't standing right in front of it and physically pointing to the building. The ramen shop has become a piece of information, instead of a physical structure, and その店 is how you'd refer to it.

    As you can see from this example, the word "the," rather than "that," is often the most natural translation of その, in this more abstract usage.

    こそあ Words for Referring to Things You Can't See

    invisible people who represent kosoa words you cannot see

    Now that we all know what we're talking about, let's move on and take a closer look at how each of the こ, そ, and あ-words work when referring to something that isn't visible.

    Although the traditional order goes こ→そ→あ, we'll start with そ-words because, out of the three, そ-words are the most neutral-sounding. Learning そ-words first will also help you to understand the other two.

    After going through the basics of all three, we'll go over more exercises for better comprehension!


    In general, when you use a そ-word, it objectively refers to the information you've mentioned previously. It suggests that the information is somewhat distant from you, conceptually speaking.

    A そ-word is more likely to be chosen if you are calm and dispassionate about the topic, or at least if you want to present yourself that way.

    When someone introduces a piece of information, the information is no longer only that person's. As soon as it's introduced, it's out of the speaker's possession and has moved to a place that is accessible by both the speaker and the people they are addressing.

    To give a physical analogy, it's like the information is placed on a tray between the people involved in the conversation, where everyone can access it. It is both a little ways away from you and a little ways away from everyone else. As explained in the ABCs of こそあど, a そ-word was chosen when pointing at something that was considered to be too far away to use a こ-word.

    In the conceptual world, it means the information is detached from everyone's subjective view, so it doesn't really hold any positive or negative significance to anyone. In other words, it's emotionally neutral. Hence, a そ-word shows that you are referring to the information objectively, without creating any obvious nuance.

    So, let's go back to the earlier example involving the rumor, which you said was not true.

    • ああ、の噂、嘘だよ。
    • Oh, that rumor is not true.

    By using a そ-word, その, you can show that you're keeping a little mental distance from the rumor you are referring to, and therefore you are referring to it from an objective point of view. In other words, a そ-word is more likely to be chosen out of the three if you are calm and dispassionate about the topic, or at least if you want to present yourself that way.

    So then, you might now be wondering, "Wait, does this mean there is a way to show excitement just by referring to something?"

    The answer is yes, and that's when the こ-words come into play!


    When a こ-word refers to the information you've already mentioned, it suggests that the information is conceptually closer to you.

    A こ-word carries a somewhat emphatic tone because it implies that you are psychologically close to whatever it is you're talking about.

    What does this mean? As explained earlier, as soon as a piece of information is introduced, it no longer belongs to one person — it's been passed on to the listeners or readers. Using a こ-word towards information that's been placed in between everyone involved is like reaching out and pulling that bit closer to you. It shows that you are informing others that you know the information better, or it holds some significance to you specifically.

    When do you think you would present information in that way?

    Sometimes, it's when you are emotionally involved in a topic (either positively or negatively) and can't help exposing that emotion. In that case, it's like you are impulsively snatching the information.

    With the scenario that was brought up earlier of the rumor about your brother, for example, you may use この when you are disgusted or disappointed by the rumor and can't hold those feelings back.

    • ああ、の噂、嘘だよ。
    • Oh, that rumor is not true.

    Since the こ-word attaches your here-and-now emotion to the thing you are referring to, it can add more vividness to the topic. In this instance, it shows that the rumor is still fresh in your memory, and you are holding a grudge about it in real-time.

    Other times, choosing こ-words shows — consciously or unconsciously — that you're more familiar with the topic. So with the same rumor example, the reason for your choice of この could also be that you think you know the details of the rumor better.

    In either case, a こ-word carries a somewhat emphatic tone because it implies that you are psychologically close to whatever it is you're talking about.

    In speaking, it's often possible to distinguish between emotional and intellectual closeness by listening to whether there's particular stress put on the こ-word or not. If the speaker is emotionally involved, they will add extra stress to the word. If they're simply implying that they know a lot about the subject, they will normally put less stress on the word.


    All right, let's get on to the last of the three! When it comes to introducing things we cannot see, あ-words work quite uniquely.

    Using an あ-word is like gazing off into the distance while remembering something.

    As a basic description, あ-words show that you feel distant from the information you are referring to. "Being distant" from the topic may seem to imply that you are unfamiliar with the topic or you are emotionally detached from the topic, but the nuance あ-words carry is quite the opposite.

    That is, with あ-words, you display you know the topic already. What's more, you can even show a sense of closeness toward the topic, if you'd like.

    But, how can you feel both closeness and distance from a topic at the same time? Well, there is a specific situation where this can happen. Can you guess what it is? It's when you look back at something from your memory!

    So, using an あ-word is like gazing off into the distance while remembering something. It demonstrates you are looking back on the already familiar information, which is stored somewhere distant in your mind. And because memory is often associated with you in a personal way, あ-words can exhibit your emotional attachment to the topic. Although this emotion can be a negative one, it's more common to conjure up closeness toward the topic, especially when talking about nostalgic memories.

    This is a lot to take in, isn't it? To see how it works, let's look at the rumor example again, but this time with あの.

    • ああ、の噂、嘘だよ。
    • Oh, that rumor is not true.

    By using an あ-word, you present that you are recollecting the encounter with the rumor. It can be used when you're simply retrieving a forgotten memory, like "Oh, that rumor!", but it can also hint at your emotions associated with the rumor, depending on how you say it.

    You've learned that こ-words can also show your emotions, but while こ displays your immediate feelings towards something, あ indicates you are looking back on the memory and experiencing emotion.

    Now, I have one more thing to say about あ-words. That is, you can also use one when you believe that you and the person you are addressing share the same or a similar memory of the topic.

    For example, imagine your friend starts talking about that same rumor again, but now it's been a month since the original conversation, and everyone knows the rumor isn't true. Here, because your friend knows that both of you are aware of the rumor, since this isn't the first time you're talking about it, an あ-word will be used.

    • の噂、覚えてる?ほんと 馬鹿ばからしい噂だったよな!
    • Do you remember that rumor? That was a really stupid rumor, wasn't it?

    So, why is あの your choice in this situation?

    This situation is actually similar to how あ-words are used with physical objects. Remember the earlier example? You and your friend are at a party, and you are looking for their cup. When pointing to a cup that's located in a place far from both you and your friend, あの is used.

    Instead of a cup, what's distant in this example is the memory associated with the rumor. Your friend knows you have information that was similarly perceived in your own memory. This means you two will end up looking at the same — or at least a similar — memory that is stored somewhere distant in each of your minds.

    Don't worry if this feels too complicated to digest right away! In the following sections, we'll explore more examples while explaining the context behind each one. These exercises will lend a hand in your grasping the core concepts of the こ, そ, and あ words!

    こそあ Words in Conversation

    two people chatting with kosoa words

    You've learned the fundamental ideas behind こそあ words, so it's time to go through more scenarios and build up your understanding! Here, we'll first check out some examples used in conversation. After that, we'll move on to examples in writing in the next section.

    To Inform Others

    The first scenario we'll examine is when you want to inform someone about something. Imagine you are talking with your friend when you remember a new ramen place that you recently tried out. You say:

    • 駅前にラーメン屋できたんだけど、[ここ・そこ]、すごく美味しいよ!
    • Did you know that there's a new ramen shop in front of the station? That place is so good!

    Although the ramen shop is a physical place, it's not there in front of you to point at. It's a piece of information you cannot see.

    By using ここ to refer to the ramen shop you can't see, you're expressing that the shop somehow feels closer to you. In this case, maybe it's because you feel that you are more familiar with the restaurant than your friend, or simply because you are excited about the delicious ramen shop and are being enthusiastic about it.

    On the other hand, if you use そこ, you're plainly referring to the ramen shop you brought up a second ago, without implying any further nuance.

    An あ-word is a bit odd to use when informing someone of something. It sounds either like you are talking about your memory in a self-directed way, or you're hinting that both you and your friend share the memory of the ramen shop, and neither nuance fits.

    However, your choice of word may change if you find out more information on the closeness of your friend to the ramen shop. For example, imagine your friend says "yes," when asked if they know about the new ramen shop. In this case, you are no longer informing your friend but sharing what you both know. So, あそこ starts feeling more acceptable, while ここ would feel a bit weird.

    In this case, ending the sentence with よ alone can be a bit odd because よ indicates you are supplying new information to them. You may want to add another particle, ね, to add the nuance of confirmation and turn it into よね.

    • あそこ美味しいよ
    • That place is good, isn't it?

    If you'd like to learn more about よ and ね, you can read an article about them here!

    To Respond to Others

    The next scenario is when you are responding to someone while referring to a topic they brought up earlier. For example, in the same ramen shop scenario, say your friend has actually been there already and responds to you:

    • あ、その店、もう行ったよ。
    • Oh, I've already been to that shop.

    The most suitable choice here is その店 because your friend is referring to the ramen shop to simply inform you of what they did. You wouldn't need to add any nuance to it.

    この is a bit strange here because it adds the nuance that your friend feels more familiar with the ramen shop than you. It was okay with the earlier rumor example because the topic was more personal and therefore close to you, but that's not the case in this scenario.

    Since this is just about where your friend has eaten, あの doesn't indicate it's a shared memory but makes it sound like your friend is recollecting their own memory of the ramen shop. So, あの also comes off as unnatural, unless your friend is saying this in a self-directed way.

    If the situation was slightly different, あの could come into play, though. For example, let's say when you bring up the ramen shop, your friend doesn't realize which ramen shop you are talking about. After a moment, however, your friend remembers that they actually have been to it before. In this case, they may use あの to refer to this lightbulb moment!💡

    • あー、あの店ね💡!もう行ったよ。
    • Ohh, that shop! I've already been there.

    To Imply Something to Someone

    We now know that あ-words can hint at a shared memory. Because of this, you can also use them to talk about something you're hesitating to say explicitly.

    For example, imagine you're in class when your teacher starts to hand out tests. By accident, your teacher drops all the papers on the floor. The student in front of you turn back and whispers:

    • 先生って、ちょっとあれだよね?
    • Our teacher is a bit…you know…?

    Here, あれ can indicate your classmate assumes you share a similar view to them and can clue into what they mean.

    あ-words can paint the speaker as a bit selfish and pushy when the assumption is not fair, though.

    Maybe they implied the teacher is clumsy. Whatever it actually means, your classmate believes you can identify the meaning from your shared knowledge, and leaves it up to your interpretation.

    あ-words can paint the speaker as a bit selfish and pushy when the assumption is not fair, though. For example, you may feel uncomfortable if you interpret あれ negatively and don't like your friend assuming you share a similar view.

    In the scenario, これ could also work, but only if you have a visual aid, like a gesture to imply what you mean, or a piece of paper that says, おっちょこちょい (clumsy). それ is odd because your classmate is referring to their subjective impression of the teacher.

    There is another implication that あ-words can create, which is to show that everyone knows what the topic is like, in general. In this way, you can use あ-words to emphasize the feeling of surprise when something is seemingly beyond everyone's expectation.

    For example, say, after the above conversation, you tell your classmate that the teacher graduated from the University of Tokyo, or the highest-ranked university in Japan. Your classmate is surprised and shouts:

    • マジ!?あの先生が!?
    • Really!? That teacher did!?

    In this example, あの implies that your classmate assumes there is some well-known understanding about the teacher — that the teacher is clumsy. It emphasizes how surprising it is that this teacher graduated from a top university.

    Here, neither この nor その is suitable. この doesn't work for implications like あの does, and その sounds strange because your classmate is not referring to the teacher from an objective point of view. 2

    An あ-word isn't always used when making implications, though. For example, imagine you are on your way to see someone you like when you run into a nosy acquaintance. They ask you where you're going, but you don't want to say any exact location. Here, you may say:

    • ちょっとそこまで。
    • Just to there.

    In this case, you respond with そこ to vaguely refer to the place you're heading, instead of あそこ. If you'd used あそこ, it would sound like you were talking about a place your friend could identify, which doesn't match the situation. ここ doesn't make sense either because it's used for indicating where you are at the moment. So to diguise the place you are off to, you'd use そこ which, in this case, simply means, "just to there." As you might have noticed, this is actually more like the physical usage of こそあど words. In this way, even when you can't see the object, sometimes people still use the こそあど words in their physical sense.

    こそあ Words in Writing

    kosoa words used in writing

    We've come to the last section, where we'll go through some examples of こそあ words in writing. Here, the writer can intentionally select one word over another to add a certain effect, depending on how they want to convey the information to the readers. Let's see how it works!

    Explanatory Writing

    In explanatory writing, you'll see a lot of こ and そ-words, but not as many あ-words. 3 So here, we'll focus on how the こ and そ words generally work.

    To learn about this, let's examine a passage from ありの行列 (The Trail of Ants) 4 :

    夏になると、庭のすみなどで、ありの行列をよく見かけます。その 行列ぎょうれつは、ありの巣から、えさのある所まで、ずっとつづいています。ありは、ものがよく見えません。それなのに、なぜ、ありの行列ができるのでしょうか。

    In the summer, I often see a line of ants in the corner of my garden. The line goes all the way from the ant's nest to the place where their food is. The ants cannot see very well. So, how does this line of ants form?

    The author starts off by talking about lines of ants he often sees in the summertime and then refers to that line using その. Since the objective そ-word is used, you can assume the author simply wanted to refer back to the trail neutrally, and then add information.

    In the next passage, the sentence structure is the same — the author brings up a new topic and refers to it in the next sentence to add more information. However, this time, この is selected over その:

    アメリカに、ウイルソンという学者がいます。この人は、次のような 実験じっけんをして、ありの様子をかんさつしました。

    In America, there is a researcher named Wilson. He conducted the following experiment to observe the behavior of ants.

    Here, the topic suddenly jumps to the researcher, Wilson. He is referred to with the word この in the next sentence. There are a couple of possibilities for the reason why この was chosen.

    One is that the author is emphasizing the importance of the information. この can indicate this because it shows the author knows something the readers don't know about the topic. In this case, that's how important the topic is, and it works as a heads-up.

    Another is that the author is aware the topic may not register easily with the readers. Earlier, we talked about how information is no longer only one person's as soon as it's introduced. However, readers can still feel somewhat distant from a topic, especially when it's something difficult and/or very unfamiliar to them. By using a こ-word, the author acknowledges this difficulty, and reassures the readers.

    After this passage, the author only uses either こ or そ-words and no あ-words. You may think そ-words would outnumber こ-words because objective references seem to be a good fit with explanatory writing. Yet, out of a total of fifteen of these words in this passage, the total number of こ-words is eight, while the total number of そ-words is seven. In this way, you'll see both こ and そ here and there in writing.

    News Writing

    You may also think そ-words would mainly be the ones used in news reports, since they're written from an objective point of view. However, こ-words are often preferred, as they are suitable for reporting firsthand news.

    For example, here is a passage from a news article about the Tokyo Olympics. 5

    国立競技場こくりつきょうぎじょうから南東に500メートルほど はなれた歩道には、閉会式の1時間ほど前から人が集まり始めました。この場所から先は通行が 規制きせいされ、閉会式の様子はほとんど分かりませんでしたが、多くの人たちが足を止めて国立競技場を写真に収めたり、スマートフォンのアプリでテレビの中継を見守ったりしていました。

    People began to gather on the sidewalk, about 500 meters southeast of the National Stadium, about an hour before the closing ceremony. Traffic was restricted from this point onward, so it was almost impossible to see the closing ceremony, but many people stopped to take pictures of the National Stadium or to watch the TV coverage on their smartphone apps.

    In this example, この can be replaced with その, but その lacks a sense of directness. It would sound like the reporter was away from the actual site and was just describing what was happening. One the other hand, using この makes it sound as if the reporter is right there and is depicting what's happening firsthand. Since こ-words can add a live feeling to the news, it's often the preferred style in news reporting.

    Using a こ-word can sound strange if the news doesn't need the live feeling though. For example, その fits in better with the following news article about a Covid-19 outbreak among students. 6

    感染かんせんした学生を ふくむ24人が先月22日からの4連休の期間中に、 舞鶴まいづる市内の飲食店で合わせて4回の 懇親会こんしんかいを開き、最大で10人の学生がマスクをせずに酒を伴う飲食をしていたということです。その後、先月28日から夏休みに入り、学生らは北海道や沖縄など18の都道府県にそれぞれ 帰省きせいしていて、帰省先で症状が出てPCR検査を受け、感染が判明したということです。

    Twenty-four people, including infected students, held four get-togethers at restaurants in Maizuru City during four consecutive holidays starting from the 22nd of last month. Also, up to ten students ate and drank alcohol without wearing masks. After that, summer vacation started on the 28th of last month, and the students returned to eighteen prefectures, including Hokkaido and Okinawa, where they had symptoms and underwent PCR testing, and were found to be infected.

    As you can see, this isn't the type of news report where the reporter can be at the site describing the situation. Instead, it's reported as a sequence of events surrounding the Covid-19 outbreak.

    Here, その is used for the point in time described in the first sentence. Replacing その with この wouldn't work because この adds a live feeling, which doesn't match the sequential events that have been collected secondhand.

    Creative Writing

    The final case we are going to share is a writing technique that creates varied effects using こそあ words. This technique is often used in creative writing when the writer introduces a new person or a new situation.

    For example, imagine the following sentence is the very first sentence of a novel.

    • [この・その・あの]日は雨が っていた。
    • It was raining that day.

    こそあ words are usually used to refer to information that was previously introduced or established. However, in this example, whichever こそあ word is chosen is referring to a point in time that is being newly introduced. None of the readers know what day the author is talking about yet, or from whose point of view it's coming from, because this is the very first piece of information.

    By using こそあ words for a new piece of information, the writer can manipulate the readers' thinking a bit. This is like when the reader thinks there is something they should know, but that something hasn't beeen revealed yet. It paints the information as uncertain and incomplete. It can create some suspense, which invokes the readers' curiosity and imagination.

    By using こそあ words for a new piece of information, the writer can manipulate the readers' thinking a bit.

    Here, この日 and あの日 suggest the writer is probably describing the day from a character's point of view because both こ and あ carry some subjectivity. Unless the author makes themselves or a specific person the narrator, a subjective viewpoint comes from one of the characters in the story. And while この日 indicates the character is describing a day as if they are reliving it or somehow wanting to emphasize it, あの日 shows they are recalling a memory.

    However, the character hasn't even been introduced yet, right? So it can naturally make the readers curious about who is thinking that thought, and why that character is talking about this day in the way they do.

    On the other hand, when the その日 is used, it doesn't give the readers information about who the story will be told by yet — it only describes the day from an objective point of view. If the writer doesn't want further implications, they will select その日 to simply convey that the story is about a specific day that was rainy.

    Wrap Up

    It would be fun to discuss a lot more examples, but unfortunately, we are wrapping up ここ (here). We've gone through quite a number of scenarios, though! So I hope you can now understand how こそあ words work when referring to things you can't see.

    As you saw, some of these uses may seem very different from English and may seem more advanced than others, but their fundamental meanings remain the same. You are now ready to take off on your own journey and try considering why one こそあ word is chosen over others. We hope you'll eventually be able to select the best こそあ choices for you in your own conversations and writing pieces.

    Enjoy spotting a bunch of こそあ words from now on. Happy studying!

    1. Although this article doesn't cover this use, こ-words can also be used to refer to something that's about to be said, as in: そして、男はこう言った。「うまい!」Then, the man said this, "Delicious!" 

    2. この先生 can work if you are simply referring to the teacher, in the physical sense. So, if this conversation happened during or right after the clumsy event, この先生が!? may be said instead. In this case, この先生 merely means "this teacher who just did something clumsy right here" and doesn't imply the sense of "we all know." In this situation, if the teacher is far away, あの先生 can still be used in the physical sense. Usually people only care if the person is near or far in the situation like this, so その先生 would come off as strange. 

    3. The use of あ is limited to when an author writes in a self-directed way — reminiscing about a memory, or hinting that the topic should evoke all (or almost all) of the readers' memories

    4. ありの行列 is compiled in the Japanese 3rd grade school textbook by 光村図書. This material was written by Tetsuya Otaki for the textbook, based on the research of Edward Osborne Wilson, a professor at Harvard University. 

    5. August 9, 2021, NHK News Web 

    6. August 13, 2021, NHK News Web