The story describes how Shinohara Satoshi who just transferred to Aoba Kita Senior School, tries to form a band which can perform during the cultural festival. However, the school rules forbids band activities. Despite so, Shinohara manages to form a five-member band including his classmate Moriyama Rin. The performance turns out to be a success but Rin collapses whereby Shinohara first learns of her suffering from a terminal illness. Just before Rin passes away, Shinohara confesses his feelings for her but is rejected by her who reacts violently to the confession. Shinohara realises that he shouldn't have done that and deeply regrets tormenting Rin with his action. 2 months after her death, Shinohara is still plagued by his guilt and accidentally goes back into time at six months ago. This time, he will try to suppress his feelings and allow Rin to leave this world with a smile.
As Murakami's role in the movie is the person who set up the band Primember, he was tasked with the role of the MC during the event. When he asked his co-stars how they felt about working with him, Yoshida and Kato both said that they felt that he was somewhat frightening at first but gradually found that he was a gentle and nice guy who could be depended on. As for Yamada who calls Murakami by the nickname Nijii, he recalled that Murakami had called him Yama-chan when they first met so he had a gut feel that they would become good friends and it turned out to be true in the end. Murakami also revealed that during the filming, as there were more actresses than actors on the set, he was sort of left out and observed them making girls' talk. In response, Yamada said that Murakami is a shy person in front of strangers so he had to help the latter connect with the others.
In line with the theme song "Natsu no owari" sung by Yoshida's band Tankobuchin, the cast were also asked what Kanji they would choose to represent their summer this year. Yamada chose the word "jump" to show his desire to achieve a breakthrough in his career since he has 6 movies released this summer. Murakami then chipped in to encourage his friend that he will definitely be able to do it since he is the busiest among them. This led to Yamada to joke that he is not as busy as Murakami which led the audience to laugh.