My Stepmom's Daughter Is My Ex

継母の連れ子が元カノだった (Mamahaha no Tsurego ga Motokano datta)

6.7(162,141)

MAL Score

Ranked #6599

Popularity #819

Comedy
Romance
School

Episodes: 12
Duration: 23 min per ep
Aired: Jul 6, 2022 to Sep 21, 2022
Status: Finished Airing

Synopsis

Bookish Mizuto Irido and quiet literature lover Yume Ayai once dated in middle school, drawn together by the same stories and sensibilities. As time passed, their differences widened, and they split up shortly after graduation—only to be thrown back into each other’s lives when their parents remarry, making them step-siblings under the same roof.

Neither is willing to concede the role of “older sibling,” and their awkward reunion quickly turns into a contest of pride. To settle it, they set a rule: whoever breaks the boundaries of proper sibling behavior loses, and the winner earns the right to be recognized as the elder—and to demand one request. But daily life together keeps stirring up old memories, and the feelings they thought they’d left behind begin to complicate the game.

Otaku Consensus

My Stepmom's Daughter Is My Ex lands as a sharply targeted but divisive school romcom: its MAL 6.72 and AniList 66/100 reflect a show that found a sizable audience without converting skeptics. What works best is Project No.9's clean, low-friction handling of domestic banter, Shinsuke Yanagi's sitcom-like pacing across a compact 12-episode run, and the adaptation's commitment to dual-protagonist pride games over harem escalation. The recurring criticism is just as clear: the inseki/cohabitation hook and boundary-testing comedy are narrow tastes, and viewers wanting broader romantic momentum may find the premise doing more work than the drama.

Why You Should Watch

Watch this if you want a school romcom built on pride, etiquette, and verbal sparring rather than a parade of rivals. It scratches a lighter version of the mind-game itch associated with Kaguya-sama: Love is War, but swaps council-room theatrics for family-life awkwardness and cohabitation tension; it also offers the taboo-adjacent charge of Domestic Girlfriend without leaning into soap-opera excess. The appeal is in small calibrations: who gets flustered first, who controls the room, and how much tsundere denial can survive ordinary household proximity. At 12 episodes, it is best for viewers who like compact romantic comedy with two clearly centered leads, literature-nerd energy, and comedy that treats social boundaries as a battlefield.

Key Characters

M
Mizuto Irido
A bookish male lead whose dry, pride-protecting restraint makes the comedy hinge on micro-reactions rather than loud romantic declarations.
Y
Yume Ayai
A quiet literature lover and tsundere-coded protagonist whose composure is most interesting when the show turns sibling etiquette into psychological warfare.

What Makes It Stand Out

1
Project No.9 produced the TV anime as a single 12-episode cour airing from July 6 to September 21, 2022, giving the adaptation a tight seasonal romcom shape rather than a long-form romantic drama structure.
2
AniList's tag weighting captures the show's unusually specific appeal: Inseki at 90%, Family Life at 75%, Cohabitation at 66%, and Tsundere at 77% place the domestic taboo-comedy angle ahead of standard school-life categorization.
3
The production is credited to director Shinsuke Yanagi and series composer Hitomi Mieno, a pairing that emphasizes episode-to-episode banter rhythm and controlled romantic escalation over action-driven spectacle.
4
The character pipeline is clearly separated in the credits: TakayaKi provided the original character designs, while Katsuyuki Satou handled the anime character designs and Keiko Kitayama handled prop design.
5
Its audience profile is stronger than its ranking suggests: on MyAnimeList it sits at popularity #820 with 160,918 votes despite a rank around #6480, while AniList records 1,848 favourites.

Fun Facts & Trivia

Fun fact 1: The original story is credited to Kyousuke Kamishiro, with Taisei Kida and Keisuke Kaminaga listed for original work assistance, indicating the anime preserved multiple source-side credits in its production listing.
Fun fact 2: TakayaKi's role is specifically credited as Original Character Design, separate from Katsuyuki Satou's anime Character Design credit, which is a useful distinction for fans comparing source art to the TV adaptation's look.
Fun fact 3: The show has a dedicated Title Logo Design credit for Tooru Inoue, alongside Lin Ge as Art Director, showing that its visual identity was broken into specialized production roles rather than folded into a single design credit.
Fun fact 4: Its reception numbers are notably consistent across platforms: MAL's 6.72/10 and AniList's 66/100 both place it in the same middle-positive band rather than showing a major platform split.
Fun fact 5: The AniList tag set includes Otaku Culture at 51% and Feet at 60%, two details that signal the anime's comedic texture more specifically than the broader Comedy and Romance genre labels.