March begins, and there is only one month left in the third term. Sakuta Azusagawa is about to celebrate the graduation of his girlfriend Mai Sakurajima. As he waits for Mai at Shichirigahama beach, an elementary school-aged girl who looks like Mai did when she was a child actress appears in front of him.
"Who are you, Mister?" she asks.
Is this a dream or an illusion? As he thinks about this mysterious experience, his father calls him.
"It's about your mother. She says she wants to see Kaede," he says.
Kaede's mother never came to terms with what happened to Kaede. Having been hospitalized for so long, their mother finally wants to see her daughter. To fulfill their mother's wish, Sakuta makes the decision to meet face-to-face — something they haven't done in a long time. He's unable to hide his nervousness about all this.
Never-before-seen scars begin to appear on Sakuta's body. Could these be warning signs of a new type of puberty syndrome?