Onii-chan's Muscles Are Done For

Onii-chan's Muscles Are Done For (お兄ちゃんの筋肉はおしまい, Onii-chan No Kin'niku Wa Oshimai) is the forty-eighth chapter of the Onimai: I'm Now Your Sister! anthology series. It is written and illustrated by Cool Kyōshinsha. It was originally published as part of Volume 3 of the anthology series on January 7, 2023.

Summary
Mahiro decides to do some strength training.

Characters

 * Mahiro Oyama
 * Mihari Oyama
 * Momiji Hozuki
 * Asahi Oka
 * Miyo Murosaki

Trivia

 * This chapter is written and illustrated by Cool Kyōshinsha.