**Height:** 177 cm He is a 1st-year post-graduate science and technology researcher at Saitama University who works closely with Ayame. After finding out that she loves him, he realizes that he knows nothing about love nor about his feelings for her, so he embarks on a series of mathematical and logical experiments with her to see if they truly love each other. He is somewhat easily embarrassed, but otherwise completely serious and logical like Ayane, keeping him stuck to her mathematical quest as well.