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'Oniichan ha Oshimai! announces TV anime adaptation by Studio Bind

The series features older brother Mahiro Oyama who becomes a woman after his little sister experiments on him.

By: Nicole S. Castro on April 22, 2022 at 10:08 PHT

Nekotoufu's comedy manga Oniichan ha Oshimai! (English title: Onimai: I'm Now Your Sister!; Alternative title: Onii-chan is Done For) has announced that it is getting a TV anime to be produced by Studio Bind, who is famous for producing the TV anime of Mushoku Tensei: Jobless Reincarnation.

See the teaser visual below.

The series stars male protagonist and gamer Mahiro Oyama, who wakes up one morning as a woman. His transformation was caused by his mad scientist little sister, Mihari, who tried one of her new experiments on him.

Below is an announcement video for the TV anime that coincides with the release of the manga's sixth volume. The dialogue introduces the Oyama siblings and their voice actors. Voice actress Marika Kouno will be voicing Mahiro Oyama in his female form while Kaori Ishihara will voice younger sister Mihari Oyama.

Oniichan ha Oshimai! is a manga series written and illustrated by Nekotoufu. It has been serialized on Ichijinsha's Monthly ComicREX magazine since June 2018 and has been compiled into six tankobon volumes as of April 2022.


  • Original work: Nekotoufu (serialized in Ichijinsha's Monthly ComicREX)

  • Director: Shingo Fujii

  • Series composition: Michiko Yokote

  • Character design: Ryou Imamura

  • Production: EGG FIRM

  • Animation: Studio Bind

Source: Oniichan wa Oshimai official Twitter, official website, Comic Natalie




Nicole is based in the Philippines and works as a freelance Japanese Translator/Interpreter and copywriter (English). She is a JLPT N2 passer who watches anime to "study" for N1. She has a long career history on LinkedIn (with primary focus on media and translation), but her anime watchlist is much, much longer.


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