Announced last year, ONIMAI: I’m Now Your Sister is Studio Bind’s latest ambitious project. What was once a niche series is now one of the bigger names in the Winter 2023 anime lineup, but does it warrant the hype?
Mushoku Tensei: Jobless Reincarnation was the breakout success of Studio Bind; but there’s a big difference between isekai fantasy and a gender bending slice of life anime. Can Bind show off the fluid animation they’ve built a reputation for in a series without magic, explosions, and fight scenes?
Whether you’ve heard about the fanservice or Studio Bind’s animation, ONIMAI has people talking. Is it worth checking out? Find out in our ONIMAI review!
ONIMAI: I’m Now Your Sister
Studios: Studio Bind
Producers: TOHO Animation, Pony Canyon, Tokyo MX
Director: Shingo Fujii
Premiere: January 5, 2023
Mahiro Oyama is a NEET who lives with his younger sister Mihari. Mihari is a genius who skipped grades and her mastery of chemistry seems to border on the fantastic. It’s thanks to a mysterious drug that Mihari turns her older brother into a middle school girl.
At first, Mihari plays it off as an experiment and she’ll need to take measurements while he remains transformed. Mahiro, who’s used to just spending his days playing eroge games can do little else but roll with it.
We quickly learn however, that beneath the obvious layer of fanservice, ONIMAI: I’m Now Your Sister is more than just gender change as a pretense for fanservice. Mihari’s experiment isn’t about the drug itself, but using Mahiro’s change as an opportunity to help “rehabilitate” him from his shut-in lifestyle.
What if you woke up one day as a girl? Where would you go? What would you do? Most importantly, what would you do differently with another chance?
That last one is the core question in ONIMAI, and maybe I’m looking for nuance and depth where there isn’t any; but I think fanservice and an inspirational message aren’t mutually exclusive. There’s a story about second chances and getting your life in order underneath all the cute bathing scenes.
It can be easy to get distracted because Studio Bind does what they do best and go hard on the animation. There’s very little jump-cuts between scenes and even something like running to the bathroom to get to the toilet gets animated with all the same care that would be given to a fight scene in Mushoku Tensei.
I’m sure you’ve noticed a trend, bathing scenes, trips to the bathroom, ONIMAI thrives in portraying the mundane. More accurately, Mahiro’s awkward encounters with his new daily life. In the first episode, Mahiro and Mihari go bra shopping, in the second Mahiro has his period. The new situations keep coming.
Later episodes, Mahiro starts going to school and things settle into a groove with friends that only know him as Mihari’s little sister. Director Shingo Fujii deserves praise for the pacing of the episodes, rather than quickly trying to introduce everyone the show takes things slowly.
There’s plenty of time between new characters to learn their names and relationship to the Oyama family. Especially Kaede Hozuki, who’s drastically different between the manga and anime. In the manga, she’s Mihari’s flashy friend from middle school. In the anime they dial it to 11 and Kaede’s a full on gyaru. It’s a needless change but it’s a matter of personal preference.
On the subject of “needless” changes, the version of ONIMAI on Crunchyroll is reportedly censored. Credit where it’s due, this decision seems to come from the Japanese publishers and not Crunchyroll itself. It sets a troubling precedent but it’s good motivation to start learning Japanese yourselves.
The voice work in the series is serviceable, but not particularly memorable. Marika Kouno, the voice of Mahiro has had few leading roles in the past, but she’s no stranger to loli characters. She had a lead role as Saki Kise in Mitsuboshi Colors.
Kouno’s ONIMAI costar Kaori Ishihara voices Mihari. Ishihara is also a voice actress who mostly has had supporting roles, but fans might recognize her as Shouta from Miss Kobayashi’s Dragon Maid.
Not every anime has to have an A-list cast and I hope the talents working on the show continue to find success; hopefully their work on ONIMAI will make them more prolific.
ONIMAI continues flexing its amazing animation with the opening and ending themes for the series. Identeitei Meltdown by P Maru-sama has a cool techno breakdown and the opening has just a hint of fanservice while introducing all of the characters. You can check it out below:
Conversely, Himegoto * Cry Sisters is a hectic song performed by the main cast including Marika Kouno (Mahiro), Kaori Ishihara (Mihari), Hisako Kanemoto (Kaede), and Minami Tsuda (Momiji).
The song features a gentle piano intro and Mahiro’s little giggle at the start is probably the best animation I’ve seen so far in the series. You can check it out below:
Ultimately, ONIMAI: I’m Now Your Sister is a well-rounded series with ample amounts of fanservice. I mentioned early in the review that I could see a prosocial theme about graduating from being a NEET that’s buried in the fanservice. I want to reiterate, it’s buried deep in the fanservice.
If fanservice is a deal breaker for you, then nothing will salvage this series for you. But if you enjoy fanservice or can at least tolerate it, there’s beautiful animation, cute characters, funny situations, and more waiting for you.
ONIMAI: I’m Now Your Sister was reviewed using a personal Crunchyroll account. You can find additional information about Niche Gamer’s review/ethics policy here.