Yuma, who cannot understand the emotions swirling within her, impulsively kisses Hotaru in the nurse's office, only to be caught by Takeda. While feeling guilty for deceiving Takeda, Yuma cannot bring herself to stop her relationship with Hotaru, which she refers to as "practice." Meanwhile, Fujiwara watches the two with a cold gaze... Yuma is in turmoil, Hotaru hides her feelings behind a smile, Takeda is filled with questions, and Fujiwara seems to be plotting something. As they conceal their intersecting feelings, the four of them head to the sea for their last summer vacation of high school...!?