Sharaku
Ordinarily he looks like your typical bullied kid—soft-featured, meek, unremarkable. But the moment that Band-Aid comes off his forehead and reveals his third eye, he transforms completely, unleashing serious supernatural abilities and sharp intellect.
In the 2004 Black Jack anime, Sharaku's a timid middle schooler who takes constant abuse from his peers. He becomes Pinoko's first real friend after she breaks up a fight involving him—which says something about both of them. Despite his cowardly streak, he genuinely cares about the people close to him and has solid knowledge of history and sci-fi trivia. He's the younger brother of Chiyoko Wato.
He's also known as "Assaji" in Buddha.
Content compiled by AnimeList.moe from publicly available sources.