Miya

His brother Atsumu calls him "Samu".
Birthday: October 5
Age: 17 years old
Height: 183.8 cm
Weight: 74.5 kg
Appearance: Upon entering high school, Osamu gained a more muscular build and stands six feet tall. Osamu is usually seen with a neutral expression, but shows excitement when he is in a game or annoyance when his brother suggests they try something new.
Personality: Osamu appears to be the calmer of the Miya twins with a laid-back and expressionless personality. Despite his outward demeanor, Osamu is very competitive and gets heated even if it's not obvious on the surface. However, with enough provocation, he gets angry and physical. In that state, he drops his filter and starts spitting out swear words. So far, his brother is the only person who has ever made him get this excited. Osamu is also shown to have a strong passion for food. He thinks about it often in the middle of a match and gets distracted by its smell. He can't seem to pick his favorite food and doesn't know what to eat as his last meal. Much like his brother, he loses self-control when it comes to eating.
Extra: When asked if he wanted to be a setter, Osamu turned it down saying that he prefers to spike. Despite that, he was chosen to be the setter for his high school team until Atsumu surpassed him. According to Aran, Osamu was the more skilled twin and Atsumu constantly challenged him.

Osamu appears to be the calmer of the Miya twins with a relaxed and deadpan personality. Despite his outward behavior, Osamu is highly competitive and gets heated even if he is not obvious on the surface. However, with enough provocation, he gets angry and physical. In that state, he abandons his filter and begins to spew profanities. So far, his brother is the only person who made him feel so emotional. Osamu has also shown to have a great passion for food. He thinks about it often in the middle of a game and is distracted by the smell. He can't seem to choose a favorite food and doesn't know what to eat as his last meal. Like his brother, he loses self-control when it comes to eating. In his second year, he decided to leave volleyball to pursue a food-related occupation, which is how he ended up establishing Onigiri Miya. He has been shown to have a sense of humor, especially regarding Atsumu, whom Osamu mocks whenever he makes a mistake.

Favorite food: food
Current concern: Not being in the mood to decide what to eat on the last day of your life.
When Atsumu and Osamu were fourth graders, they found Ojiro Aran cool because of his foreign-sounding name.
The Miya brothers went to the same high school as Ojiro Aran. Although Coach Ukai listed Osamu, and by extension Atsumu, at age 16, the Miya twins should have already turned 17 at Spring Interhigh due to their birthday in October.