BuBu ChaCha (1999)
Original title: ぶぶチャチャ
BuBu ChaCha is a 1999 Japanese-language animation series created by Tetsuro Amino. It stars Atsuko Tanaka, Taeko Kawata and Yuuko Sasamoto.
Randy and ChaCha (Randy's pet dog) are best of friends. One day, ChaCha passes away, and turns into a star to watch over Randy. But ChaCha decides to return to Randy in the form of a toy car. Randy and ChaCha keep this secret to their own selves, and off they go to their adventures, where they learn that every little thing is a big discovery.