Summer... A classroom in a high school by the sea. As Kumiko, a world history teacher, walks between the students' desks, a male student suddenly takes her hand. In the notebook of that student—Eiji—the word "Love" is written in large letters. Kumiko, who lost her boyfriend Yusuke in a motorcycle accident two summers ago, finds a sincere heart beneath Eiji's rough exterior and gradually finds herself drawn to him. "Why don't we go? On my bike. To the sea—the same sea where you spent your last moments with him," Eiji says, holding a photograph of Yusuke. Donning Yusuke's helmet and holding Eiji in a tight embrace, Kumiko feels a burning, passionate summer come alive within her once more.