Wabisuke, the illegitimate son of Sakae's late husband, was adopted by the kind woman when he was just a child. He is a talented computer programmer, and works as a professor at Carnegie Mellon University. As Natsuki's half-great-uncle, the man holds a special place in her heart and, like many in his family, is a talented Koi-Koi player. Due to his illegitimacy, Wabisuke was shunned by the Jinnouchi family and thus, the man comes across as cold-hearted to everyone. But deep down, he cares deeply for Sakae.