Kappa no Kû to natsuyasumi

A young boy named Kōichi Uehara finds a stone in a muddy ditch that contains a miraculously surviving kappa, Coo, 200 years after its father's murder. Coo is taken in by the Uehara family and, with the help of their dog Ossan, searches for other remaining kappa. As Coo's presence becomes public, he is ambushed by journalists and paparazzi, leading to a series of events that test the family's bond and Coo's determination to find his people. Ultimately, Coo finds a kijimuna cousin in Okinawa, who promises to teach him how to change his appearance, marking the beginning of a new journey for the lone kappa.