Mahiro and the Terrifying Secret Room

Mahiro and the Terrifying Secret Room (まひろと恐怖の密室, Mahiro To Kyōfu No Misshitsu) is the eleventh chapter of the Onimai: I'm Now Your Sister! anthology series. It is written and illustrated by Kometsubu. It was originally published as part of Volume 1 of the anthology series on May 27, 2021.

Summary
Mahiro and Mihari become trapped in an elevator on a hot day while buying swimsuits.

Characters

 * Mahiro Oyama
 * Mihari Oyama

Trivia

 * This chapter is written and illustrated by Kometsubu.