Toshiyuki Morikawa
is a professional shogi player, as well as the former boyfriend of Yumi Miyamoto. He is widely known by the name of in the world of shogi. Yumi nicknames him because he keeps eating cheese like a mouse which makes a noise that sounds a lot like 'Chu'. He is also the middle brother of the Akai family, making him the sibling of Shuichi Akai and Masumi Sera. His Japanese voice actor is Toshiyuki Morikawa.