Keito is the older brother of Chiaki, currently in Grade 12. He's cold to everyone and brutally honest no matter who you are, but he does care deeply about the people he's close to. He happens to be a huge nerd, as well as an extremely smart individual.

Keito is, yet again, another person with a medium-low voice, however his regular tone is normally set at close to monotone, however there's some emotion in his voice if you listen closely.