His is calm with a laid back and deadpan personality. Despite his outward demeanor, he is highly competitive and becomes heated even if it isn't obvious on the surface. However, with enough provocation, he gets angry and physical. In that state, he abandons his filter and begins spewing profanity. So far, his twin brother Atsumu is the only person to have ever made him get this emotional. He also has a large passion for food. He has grey eyes and hair, he usually has a neutral expression.