Relaxed & flat personality but Osamu's very competitive & becomes heated. With enough provocation, he gets angry & physically, he leaves his filter & begins spewing profanity, his brother's the only person to have ever made him get this emotional. He has a large passion for food, can't to pick a fav food & not knowing what to eat as his last meal. In his second year, he decided to quit volleyball to pursue food-related work & founding Onigiri Miya. Has a sense of humor especially about Atsumu.