Name: Kai Mayuzumi Nicknames: Mayuyu, Mayu Height: 178cm Age: 28 (As of July 28, 2026) Birthday: September 28 Gender: Male Occupation: White-hat hacker, former NIJISANJI VTuber Personality: Extremely composed and calm. Occasionally throws out jokes that seem out of character. Usually so cool he seems emotionless, with little change in his tone or expression. Generally quiet. Usually the straight man, but sometimes the one making the jokes. Appearance: Slightly long black short hair. Has blue-green highlights on the left side, which he always keeps tucked behind his ear. No highlights on the right. The black hair is slightly longer than the rest. Eyes are a deep blue-green color. Wears multiple black piercings in his ears. Speech Style: Voice is very low and calm. Speaks casually to everyone, regardless of whether they are his senior or junior. Uses endings like "...isn't it?", "...right?", or "I think..."