200 years later in modern-day Tokyo, Kōichi Uehara is peer pressured by his friends to pick on the quiet Sayoko Kikuchi, whom they continue to call ugly.

They name the kappa Coo, as he has forgotten his real name, and he quickly warms up to the family, though Kōichi's younger sister Hitomi has a strong disdain for him, but slowly she too accepts him.

Coo later learns from Ossan that he had a previous owner who loved him, but that one day he started getting beaten up by him due to the stress of school.

Coo once again uses his abilities to blow up a bird that was planning to eat Ossan before climbing up a radio tower with his father's arm.

As he considers killing himself, the sky suddenly begins to rain and a water elemental dragon appears; convincing Coo to keep living.

Coo ventures in the lush greenery of his new surroundings with his father's arm; promising to continue his search for more kappa and to one day see the Ueharas again.

There are other Japanese mythical creatures appearing in the movie: Over a decade after its debut, the film became widely available in a native English-speaking region for the first time when, in the United States and Canada, it was released direct to home video on January 21, 2020, by GKIDS.