YMMV / ONIMAI: I'm Now Your Sister!

• Americans Hate Tingle: The anime was not well-received by American audiences due to its premise combined with its ecchi elements (which are much more rampant compared to the original manga, especially in the first episode). The show also received flack from the transgender community due to Mahiro not consenting to a sex change and for including elements of gender essentialism (essentially, the manga/anime hammers in the perception that "girls have to like girly things instead of video games", at least early on, and an early scene has Mihari see Mahiro play a Boys' Love eroge and assume that he's into it now because he's a girl). In Japan and the rest of Asia, these themes aren't discussed as seriously in most media. Combined with Japanese and Asian audiences being less put off by the more ecchi aspects of the show and it became the top-rated anime of the Winter season.
• Awesome Art: The animation for the anime adaptation is amazingly fluid and lively for what is just a mildly ecchi schoolgirl comedy. Even among its detractors, the animation alone is universally well-regarded as one of the best to come out of a 2020s anime.
• Memetic Mutation:
  • "ARI NASHI, NASHI ARI"^ExplanationThe first words from the opening song, extremely catchy due to their repetition.
  • "It's Oyama's fault."^ExplanationMost likely inspired by the "It's Shamiko's fault" meme from The Demon Girl Next Door, this line is often used in fanart whenever Mahiro is accosted by the boys (or sometimes Momiji), or is generally being a seductress.
    • Eventually ascended in the artist's Pixiv commentary on chapter 75.
• Overshadowed by Controversy: For western audiences, Onimai was seen as this during the anime's original winter 2023 release. Most of them either refused to give it a chance due its contentious presentation, or felt it was unbearable to sit through because of it. However, for Japan, it was a major success, quickly becoming one of the best selling releases for the Winter 2023 anime season.
• Signature Scene: Mahiro's reaction to Kaede's swimsuit in her introduction episode in the anime.
• Tainted by the Preview: Again, mainly in the west. Before the anime was released, many had already written it off, since the series had ecchi elements and the premise (turning an adult guy into a younger girl for rehabilitation) was well into otaku territory. The release of its opening, before the first episode aired, didn't help matters for those who already had a disdain for Onimai and thought it was too weird. This infamous semi-viral share of the opening from December 2022, a month prior to its premiere, received incredibly negative reception from western audiences, further causing more people to avoid Onimai. Not even its censorship could save its controversial status in the west at the time of its original broadcast.
• Values Dissonance: When Mahiro tries putting on tinted lip balm, a teacher at school reprimands him for it and tells him that makeup isn't allowed. This may seem rather harsh to a North American audience, since at most schools in Canada and the US wearing makeup isn't a big deal at all (especially not lip balm, whichcis considered a moisturizer or ointment), but many Japanese schools have very strict dress codes and it's not unusual for makeup to be prohibited (and other characters, Mahiro included, do lament how unfair that is).

---