Ever since they returned from the Hell of Mirrors, Nene and Hanako-kun have seen how depressed Kou has been. Deciding to cheer him up, the three friends head to the Tanabata festival inside one of the Boundaries in the school. However, instead of a fun night with friends, Nene finds herself sent back fifty years in time to come face to face with a living version of Hanako-kun.

Translation of: Jibaku shonen Hanako-kun. "First published in Japan in 2018 by Square Enix Co, Ltd."--Copyright page. Cover title. Printed Manga-style; book opens from left to right. Pages are read from right to left.