Oniichan wa Oshimai!

Onimai: I'm Now Your Sister!

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Alternative Titles

Synonyms: Onimai, Onii-chan is Done For
Japanese: お兄ちゃんはおしまい!
English: Onimai: I'm Now Your Sister!
More titles


Type: TV
Episodes: 12
Status: Finished Airing
Aired: Jan 5, 2023 to Mar 23, 2023
Premiered: Winter 2023
Broadcast: Thursdays at 23:30 (JST)
Licensors: None found, add some
Studios: Studio Bind
Source: Manga
Genre: ComedyComedy
Themes: CGDCTCGDCT, Magical Sex ShiftMagical Sex Shift, SchoolSchool
Demographic: ShounenShounen
Duration: 23 min. per ep.
Rating: PG-13 - Teens 13 or older


Score: 7.681 (scored by 6656266,562 users)
1 indicates a weighted score.
Ranked: #12522
2 based on the top anime page. Please note that 'Not yet aired' and 'R18+' titles are excluded.
Popularity: #1582
Members: 141,458
Favorites: 1,972

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Ranked #1252Popularity #1582Members 141,458
Add to My List
Episodes: /12


Self-professed "home security guard" Mahiro Oyama has not left his home in years, secluding himself in his room playing erotic visual novels. This depraved lifestyle causes his prodigious sister, Mihari, to worry about his well-being. In hopes of solving this problem, she devises a plan to rehabilitate him back to normalcy.

The first part of Mihari's plan is to concoct a medicine that changes her brother's biological constitution into a bona fide female, much to Mahiro's vehement dismay. Stuck in this predicament, Mahiro has no choice but to live out his life as a cute girl until the effect wears off—if it ever does.

[Written by MAL Rewrite]


Oniichan wa Oshimai! was released on Blu-ray in two boxes from April 19, 2023, to June 21, 2023.

Episode Videos

Related Anime

Characters & Voice Actors

Murosaki, Miyo

Hioka, Natsumi

Fujimi, Nemu

Sakurai, Mia


Uchida, Yuuya

Nagase, Miyako

Oda, Karin

Kitahara, Yuriko

Nagae, Rika


Hatakeyama, Takurou
Higashi, Mao
Assistant Producer


Opening Theme

Apple Music
Amazon Music
Youtube Music
"Iden Tei Tei Meltdown (アイデン貞貞メルトダウン)" by Enako feat. P-maru-sama. (P丸様。)


Mar 23, 2023
Like many, I was impressed with the debut of Studio Bind and their highly-anticipated, highly-praised, highly-controversial anime adaptation for Mushoku Tensei: Jobless Reincarnation, and like so many more, I was already getting excited for its second season as soon as its first came to a close. However, also like many, I proceeded to be half-disappointed, half-confused when I saw the announcement for Oniichan wa Oshimai! with the name of Studio Bind—the studio which I thought was created for the sole purpose of adapting Mushoku Tensei—so proudly attached. A veteran animator like Shingo Fuji making a directorial debut at a studio I can actually trust to ...
Mar 23, 2023
Mixed Feelings
The only reason why I decided to give this anime a shot is because of the fact it was going to be animated by Studio Bind. Therefore, I thought... "Why not? Looks interesting to me. A gender-bender anime about a failure in life who became a loli by his or should we say 'HER' now to give HER a second chance in life." Now I know what you're thinking, if you look into this out of context, it's essentially a story about a fully grown man who's living alongside middle schoolers who don't have the slightest idea of this PERSON's past, yet it's treating it ...
Jul 17, 2023
I must admit that I cannot understand why someone could enjoy an anime like this one.

This anime doesn't work for any audience. For example, if you are a fan of the Sex Shift genre or a fan of CGDCT stories, I can assume that you are part of a female audience that will hate the dose of fan service of this anime.

On the other hand, if you enjoy the fan service, I assume you are a male audience that won't enjoy the homo reference of the Sex Shift genre and that you don't enjoy the CGDCT anime.

Additionally, this anime won't contribute to anything in your ...

Interest Stacks


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Recent Forum Discussion

Poll: did this show get you excited
weeaboo5008 - Dec 26, 2023
23 repliesby PeripheralVision »»
Feb 9, 11:44 AM
I love Asahi!
BigBoyAdvance - Feb 7
19 repliesby Floelle »»
Feb 8, 2:36 AM
Poll: Oniichan wa Oshimai! Episode 1 Discussion ( 1 2 3 4 5 ... Last Page )
KANLen09 - Dec 24, 2022
332 repliesby vvinrg »»
Jan 28, 11:25 AM
Mihari seems like an awful person
8bit_meat - Jan 2, 2023
25 repliesby LangleyAsuka »»
Jan 25, 8:17 AM
Poll: Oniichan wa Oshimai! Episode 3 Discussion ( 1 2 3 4 )
Stark700 - Jan 19, 2023
171 repliesby ilikemangaig »»
Jan 22, 2:20 PM