Gian's uncle is Gian's maternal uncle. He is a black belt in judo. He taught Gian to use his strength in helping the weak. He also teached his nephew judo.

Gian is his nephew. Gian respects his uncle a lot. He wanted his uncle to teach him Judo for more strength. But his uncle refuses and says that Judo must be used only for good things.

(Source: Doraemon Wiki)