Mahiro Oyama
main character
TV
7.5
My TrackerPLANNING
Episode: 0 / 12
My Score:
Anime DetailsFINISHED
Estimated watch time
4h 48m
⚡ 3 days at 5 eps/day
Tags & Tropes
Gender Bending97%Primarily Female Cast94%Rehabilitation94%Age Regression94%Cute Girls Doing Cute Things93%Female Protagonist87%Primarily Teen Cast87%Coming of Age86%Hikikomori83%Family Life81%
TVFINISHED2023 WINTER7.5 / 10 AniList score
ONIMAI: I'm Now Your Sister!
お兄ちゃんはおしまい！• Onii-chan wa Oshimai!
Synopsis & Story
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! (Source: Kodansha USA)
Trailer
Watch on YouTubeWhere to Watch Officially
Availability, audio and subtitles vary by region and service.
Featured Cast & Voice Actors
Franchise Universe & Related Entries
Aniphoria guide
ONIMAI: I'm Now Your Sister!: should you watch it?
At a glance
ONIMAI: I'm Now Your Sister! has been well received, with an average AniList score of 75/100 — 62% of 25,763 ratings are 8/10 or higher.
It ranks #51 highest-rated anime of 2023, and #64 most popular anime of 2023, and #12 highest-rated anime of Winter 2023 on AniList.
Of the 54.5K AniList users who started it, 8.4% dropped it, so it is dropped at a typical rate; 40.1K have finished it.
At about 4 h 48 min in total, it is a short commitment — a weekend binge.
Best for viewers who enjoy Comedy, Ecchi, Slice of Life — especially gender bending, primarily female cast, rehabilitation, age regression.
Episodes
12 episodes are listed.
Main cast & creators
- Original creator
- Nekotofu
- Director
- Shingo Fujii
- Series composition
- Michiko Yokote
- Character design
- Ryou Imamura
- Music
- Alisa Okehazama
- Music
- Daisuke Achiwa
ONIMAI: I'm Now Your Sister! FAQ
- How many episodes does ONIMAI: I'm Now Your Sister! have?
- ONIMAI: I'm Now Your Sister! has 12 episodes of about 24 minutes each, roughly 4 h 48 min in total.
- How long does it take to watch ONIMAI: I'm Now Your Sister!?
- About 4 h 48 min back to back. At two episodes a day it takes 6 days; at one hour a day, about 5 days.
- Is ONIMAI: I'm Now Your Sister! finished?
- Yes. ONIMAI: I'm Now Your Sister! has finished airing — the final episode aired March 23, 2023.
- Is there a season 2 of ONIMAI: I'm Now Your Sister!?
- No sequel is listed for ONIMAI: I'm Now Your Sister! as of October 2026. You can continue the story in the original manga.
- Is ONIMAI: I'm Now Your Sister! based on a manga?
- Yes. ONIMAI: I'm Now Your Sister! adapts the manga by Nekotofu.
- Who animated ONIMAI: I'm Now Your Sister!?
- ONIMAI: I'm Now Your Sister! was animated by Studio Bind and directed by Shingo Fujii.
- Where can I watch ONIMAI: I'm Now Your Sister!?
- ONIMAI: I'm Now Your Sister! is listed on Crunchyroll, YouTube, Bilibili TV, Laftel. Availability varies by region — check the streaming links on this page.