Kotarou, a mysterious 4 year old, begins living in an apartment on his own. For some reason, he's perfectly capable of taking care of himself, despite the concerns of his neighbors.

Kotarou wa Hitorigurashi won the Electronic Manga Award in the Boys' category in 2018. The manga was adapted into a Japanese live-action TV series that aired from April 24, 2021, to June 26, 2021. A second season aired from April 15, 2023, to June 10, 2023.