Known as Jouro, Amatsuyu Kisaragi may seem unremarkable despite his friendly demeanor, unlike his charismatic best friend Sun-chan. Secretly, Jouro is scheming to win the affections of two girls, including his childhood friend and the student council president, in his 'perfect harem plan.' However, his plot takes an unexpected turn when both girls confess their love for Sun-chan instead and want Jouro's help. To add to the chaos, Jouro discovers that the reserved Sumireko Sanshokuin is interested in him but is intent on disrupting his schemes with her challenging personality.