Every day after school, he visits the home of his reclusive childhood friend, a girl one year younger named Midori Ibutsu. She has an unusual habit of closely sniffing Masato’s scent, burying her face in him every time he visits.

Having been bullied in middle school, she became a shut-in and was even abandoned by her parents, leaving Masato as her entire world. She’s so devoted to him that she’d say she’d “do anything” to avoid being abandoned by him.

One day, Masato is confessed to by a classmate named Kurusu. However, after confessing her love, she flees, leaving Masato no choice but to plan to respond the next day.

But the following day—Kurusu vanishes. And no one remembers her.

It’s as if she never existed in the first place—.