The summer vacation has ended and a new semester begins, but Nanabi is bedridden with a cold. Surprisingly (?), Mitsui Sona takes care of her with kindness, and Nanabi starts to open her heart. Of course, the battle for Nanabi between Fujiwara Konomi and Takamura Iori unfolds fiercely, from ping pong at the hot springs to a double-booked date at the shopping mall. Meanwhile, the unexpected past of the usually carefree Tsukishiro Yuu is also revealed... Volume 4 adds a slightly bitter taste to the usual lucky pervert and harem!