When his parents relocate for work, Kazunari Usa embarks on a solo journey as a high school freshman. Eager for a tranquil teenage life, he moves into the Kawai Complex boarding house, only to encounter a motley crew of eccentric residents. From his perverted and masochistic roommate Shirosaki to the love-weary office lady Mayumi Nishikino and the flirtatious college student Sayaka Watanabe, Kazunari is surrounded by peculiar personalities. Just as he contemplates leaving this peculiar abode, he crosses paths with the introverted senior student Ritsu Kawai, sparking a gradual blossoming of affection within him.