ONIMAI: I’m Now Your Sister! will premiere on January 5 as part of the Winter 2023 anime season.
ONIMAI is a light-hearted comedy series that follows Mahiro Oyama, an otaku who lives with his mad scientist younger sister Mihari. As part of an experiment (i.e. prank), Mahiro’s sister turns him into a young girl and refuses to change him back!
ONIMAI: I’m Now Your Sister! will be the second series from Studio Bind, a relatively new studio founded in 2018 who made a name for themselves with their first anime production: Mushoku Tensei: Jobless Reincarnation. You can check out the latest trailer here.
The series began in 2017 and is serialized in Monthly Comic Rex in Japan under the title Onii-chan wa Oshimai! (Onii-chan is Done For!).
You can read a summary of the series from MyAnimeList below.
Mahiro Oyama was just a normal erotic-game loving dude…until he woke up one morning as a woman! Turns out his mad-scientist little sister, Mihari, tried out one of her new experiments on him… with a disastrous outcome, as far as Mahiro’s concerned! But Mihari is as determined to study him as he is determined to go back to his shut-in, game-playing life, and one thing’s for sure… life is going to get a whole lot weirder from here on out!
The manga is published in English by Kodansha USA.