Onimai: I'm Now Your Sister! (manga)

Onimai: I'm Now Your Sister! (お兄ちゃんはおしまい!, Onii-chan wa Oshimai!) is a Japanese manga series written and illustrated by Nekotofu. The series has been serialized online since 2017; it is also currently serialized in Ichijinsha's Monthly Comic Rex magazine since April 2019. It is licensed in English by Kodansha USA. An anime television series adaptation by Studio Bind premiered in January 2023.

Plot
The series follows Mahiro Oyama, an otaku living with his scientist younger sister Mihari. One day he wakes up as a young girl, a result of one of Mihari's experiments. Mahiro must now learn to live as a middle school girl, all while making friends in his new school.

Characters
Mahiro Oyama (緒山 真尋, Oyama Mahiro)

Mihari Oyama (緒山 みはり, Oyama Mihari)

Kaede Hozuki (穂月 かえで, Hozuki Kaede)

Momiji Hozuki (穂月 もみじ, Hozuki Momiji)

Asahi Ōka (桜花 あさひ, Ōka Asahi)

Miyo Murosaki (室崎 みよ, Murosaki Miyo)

Chapters
Written and illustrated by Nekotofu, Onimai: I'm Now Your Sister! began serialization online via Pixiv and other platforms in 2017. It also started in Ichijinsha's Monthly Comic Rex magazine on April 27, 2019. As of January 2023, seven tankōbon volumes have been released by Ichijinsha. In North America, Kodansha USA is publishing the series in English. In Germany, Manga JAM Session publishes the manga as Ab sofort Schwester!.