Mamahaha no Tsurego ga Motokano datta or The Child of Stepmother Was The Ex-Girlfriend is a Japanese romantic comedy light novel series by Kyōsuke Kamishiro and Takayaki illustrated it. Kakuyomu serialized the series as from August 2017 and print version began publication under Kadokawa Shoten‘s Kadokawa Sneaker Bunko in December 2018.
North America licensed the light novel by J-Novel Club. A manga adaptation of the light novel began serialization online by Fujimi Shobo via Niconico Seiga. We equally have n anime adaptation with it trailer that has each over 1M views. My Stepmom’s Daughter is my Ex set to Premiere in July 6, 2022 will give you a lifetime experience
J-Novel Club describes My Stepmom’s Daughter Is My Ex as follows:
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.