High school student Uenoyama Lixia is shocked by the singing voice of Midwinter Sato, and joins Midwinter as a vocalist in a band with Haruki Nakayama and Akihiko Kaji. After joining Midwinter for the first time, the band "Given" started their activities, and Lixia became aware of their feelings for Midwinter and started dating. Members who have entered the summer vacation and are practicing for the next live that has been given the right to participate in the festival. However, in the middle of winter, I was stuck in writing a new song. It was the beginning of summer watching over such midwinter, but the two collided with each other due to a trivial trigger...