![](https://cdn.animecharacters.io/images/anime/large/21337-c9def5a2.jpg)
Format
TV
Episodes
12
Episode Duration
23 min per ep
Status
Finished Airing
Premiered
Summer 2022
Aired
2022-07-06 to 2022-09-21
Source
Light novel
Rating
PG-13 - Teens 13 or older
Genres
Comedy
Romance
Studios
Project No.9
Producers
Sotsu
Pony Canyon
Movic
AT-X
KlockWorx
Asmik Ace
BS Fuji
DMM pictures
BS NTV
Kadokawa
Yomiuri Shimbun
APDREAM
Bit grooove promotion
Happinet Phantom Studios
Bergamo
Licensors
Mamahaha no Tsurego ga Motokano datta (継母の連れ子が元カノだった)
Listless geek Mizuto Irido and introverted nerd Yume Ayai seemed like a match made in heaven, connected by their mutual love for literature. Unfortunately, their differences gradually grew, and they separated just after their middle school graduation. But, as if by divine comedy, the two find themselves reunited as step-siblings. A rivalry begins to brew between the former couple, both unwilling to acknowledge the other as the older sibling. In an attempt to "solve" this issue, Mizuto and Yume agree upon a rule: whoever crosses the boundaries of siblinghood norms loses, and the winner will not only be called the older sibling, but also get to make a request. However, now that they live under the same roof, the lingering memories they share start to influence their actions—possibly rekindling the feelings that may not have been fully extinguished in the first place. [Written by MAL Rewrite]