Tenkōsaki no Seiso Karen na Bishōjo ga, Mukashi Danshi to Omotte Issho ni Asonda Osananajimi datta Ken

Hayato arrives at his new high school carrying a secret from seven years ago. He made a promise to a childhood friend he believed was a boy named Haruki during their summer adventures together. When he finally reunites with this person at his new school, the reality hits hard: Haruki is actually a girl who kept her hair short and dressed tomboyishly to maintain that specific friendship dynamic.

Yu Hibari crafted this narrative as a romantic comedy that explores the awkward shift from platonic playmates to potential lovers when the foundation of their relationship changes. The story balances humor derived from Hayato's internal confusion with genuine emotional stakes regarding trust and identity. While the first volume leans on familiar tropes, later installments expand into family drama and deeper character development as the duo navigates their new reality in a different environment.

The series began its life on the Shōsetsuka ni Narō platform in June 2020 before Kadokawa Shoten acquired it for their Sneaker Bunko imprint. Illustrations by Shiso defined the visual style throughout the run, which concluded with the release of the eleventh physical volume in July 2026. This print run was complemented by a manga adaptation illustrated by Kina Ōyama and an anime television production by Project No.9 that aired during the same year. [edit]