With his parents often away for work, Natsukawa Ryota had become responsible for caring for both his younger sisters as well as housework; but now that he will soon be attending University he looks forward to living freely on his own! He's shocked when it turns out his roommate will be his childhood acquaintance Tanaka Kazuhito; an attractive yet pleasant young man without a date in sight despite all appearances of happiness and good looks. Ryota follows Kazuhito to investigate why, yet finds himself unable to pinpoint any faults with him or with what has transpired between them; their conversation turns romantic as their feelings blossom into relationships between each other - eventually leading them both down a cohabitation path where each is aware of each others presence!...
