My Stepmom's Daughter Is My Ex (継母の連れ子が元カノだった Mamahaha no Tsurego ga Moto Kano datta?) is an anime adaptation of Kyousuke Kamishiro's Romantic Comendy light novel series that was officially announced on January 27, 2022 . The series production led by Project No.9.
The Light Novel series has been published from Kadokawa Sneaker Bunko imprint since December 2018. A manga adaptation is released on the Niconico Seiga since May 2019.
Ah, high school. Is there any better place to start fresh after a horrible middle school relationship? Nope! Not unless your ex ends up at the same school as you and is now your stepsibling. What was supposed to be a sanctuary of peace where I could avoid ever seeing her again has become a living nightmare! Everywhere I look, I see her—in my house, in my school, in my class. There's no escape! She even claims that she’s the older sibling. Like hell she is! But I won't lose to her. After all, I'm the older brother in this new family situation. That’s right, we’re family now. No matter how much we may have thought we loved each other before, we saw one another’s true colors and realized we weren’t meant for each other. That’s why even though we may keep up a buddy-buddy sibling act for the sake of our parents, things will never go back to the way they used to be.
- Original Creator: Kyousuke Kamishiro
- Original Character Design: Takayaki
- Director: Shinsuke Yanagi
- Series Composition: Deko Akao
- Script: Deko Akao
- Character Design: Katsuyuki Sato
- Animation Production: Project No.9