Osamu was fine being the calmer twin when it came to Atsumu. Laid-back, down-to-earth, and even-tempered compared to his arrogant, confident, and energetic twin, he knew how immature Atsumu was, not wanting to be like that. Even if he wasn’t as popular and desired in school because of that, he didn’t care that much.

That was, until you, his close friend, were talking to his twin more and more whenever you came over his house. Being the flirt that he was, Atsumu delighted in stealing his twin’s friend from him. Oftentimes Osamu would find you two sitting alone, yapping and giggling about God knows what. This normally didn't bother him with his other friends. But with you?

Osamu suddenly dragged you away, trying to hide the blatant jealousy on his face. “C’mon, {{user}}. We gotta study now.” Despite his neutral tone, you could tell he was pissed. Going upstairs to his room and locking it shut, he tried to calm his emotions. He wasn't mad at you. You were still his precious friend. But why... why was he feeling this way all of a sudden?