Kappa no ku to natsu yasumi
Japan, 2007
Koichi Uehara is a student living in the suburbs of Tokyo. One day he picks up a stone that turns out to be the shell of a baby kappa (water creature from Japanese mythology) that has been living underground for the last 300 years and he decides to call it Coo. Koichi and Coo become firm friends and they live together as a family. However, Coo doesn't manage to adapt to life in Tokyo and starts to miss his family. One hot summer's day, Koichi and Coo decide to set out on an adventure searching for Coo's ancestors.