I've always thought Leo (Kimba) from the 1989 series The New Adventures Of Kimba The White Lion was a lot like Gin from Ginga Nagareboshi Gin. They're both very kind-hearted and selfless, but also a bit impulsive. Also, they both have a human friend who used to be their owner (Leo with Kenichi, Gin with Daisuke).
Gin (c) Yoshihiro Takahashi
Leo/Kimba (c) Osamu Tezuka
Bases (c) rurounigemini83 and Sakujo on GingaBoard