Katashi comes across as cold and uncaring, but as the story progresses, he reveals more of his personality that no one has seen before. He's very stubborn, and refuses to believe he's going soft until he has no choice but to accept it.

His voice is deep, and emphasizes his cold and unforgiving nature. He doesn't express emotion through his voice, making it very monotone. A good example would be a male version of Kyoko Kirigiri from Danganronpa: Trigger Happy Havoc.