This is Keiichi Maebara. He's the main protagonist of most of the question arks. He is the son of a famous artist Ichiro Maebara. His specialty is using his speeches to influence other people around him (as the club members calls him the "Magician of Language"). His strength of believing his friends are incredibly strong, and he's believe to be the one of the keys of solving the mystery of 58th year of Showa era.
