If you aren't the type for sweet obsessions or fluffy romance, Erased might be more your style. It's the live action adaptation of a manga known as 僕だけがいない街 in Japanese.
Erased is more like an anime compared to what we usually recommend, but there are some interesting things you can gain from it. As with most dramas, the main character and most others speaks slowly, which makes it easier to follow. Because there are flashbacks, you get to hear childhood slang and Hokkaido dialect. If you live in Hokkaido (or want to someday), you can use this show to learn a thing or two, with the help of a guide we wrote.
The content, however, is kinda creepy. And you won't get as much vocabulary out of it as you would with a slice of life drama either. But if you need a gripping thriller with time travel to get you interested in using shows to learn Japanese, then this is a solid choice. Erased covers some dark themes though, so it won't be for everyone.