Kingyo no Isshou
English name: Short and Happy Life of a Goldfish
Genres: Slice of Life
Type: Movie, Episodes: 1
Aired: 1993
Source: Original
Rating: PG - Children
Synopsis:
An elementary school student named Mitsui won a goldfish at a summer festival. He took it home as a pet, and for a while, it attracted his attention. However, once he received a pet a turtle for Christmas, he began to lose interest in the goldfish.

(Source: Official Site)