Gunma

Gunma is a scientist raised by Dr. Takamatsu. He is childish and eccentric and a bit of an airhead, and has a slight obsession with designing his inventions to look like swans. He originally thought his father was Luzar but it turned out to be Magic. He is Kotaro's only biological brother. While technically Magic's eldest son, after it was revealed that he and Shintaro were switched at birth