Natsukawa Ryota, looking forward to university, is surprised to encounter childhood friend Tanaka Kazuhito as his new roommate. Thus begins their journey of working together to ascertain why seemingly-perfect Kazuhito is still single.

With his parents frequently away for work, Natsukawa Ryota had been the main caretaker for his younger sisters and the housework, but now he's finally about to go to University, he's looking forward to being able to live freely on his own! However, in a surprising turn of events, he's surprised to discover his roommate will be his childhood friend Tanaka Kazuhito. Despite his picture-perfect looks and pleasant personality, Kazuhito doesn't have a girlfriend. Curious, Ryota accompanies him in searching for the reason why, but is unable to find any flaws and finds his heart fluttering over Kazuhito's kind words and actions. As he gets to know more about Kazuhito, their relationship develops. Thus begins their cohabitation life where they're mutually self-aware of each others presence!