Yasuo Tanaka

Yasuo Tanaka (referred to as Yamada in the 1979 anime) is one of Nobita's classmates and a background character. He is distinguishable by always wearing a baseball cap. He often appears with Haruo. He is often credited in the credits as Boy A (少年A). Yasuo has a younger sister, as seen in the 2005 anime episode The Horror of Gian's Pizza. (Source: Doraemon Wiki)