My Stepmom's Daughter Is My Ex Anime Casts Yōko Hikasa, Hinata Satō

The official Twitter account for the anime of Kyōsuke Kamishiro and Takayaki's My Stepmom's Daughter Is My Ex (Mamahaha no Tsurego ga Moto Kano Datta) light novel series revealed two new cast members for the anime on Monday. Yōko Hikasa will play Madoka Tanesato (first image below), while Hinata Satō will play Chikuma Tanesato (second image below). The characters are Mizuto's cousins, and will appear in the anime's 11th episode on Wednesday.

The anime premiered on AT-X and Tokyo MX on July 6, on BS NTV and MBS on July 9, and on BS Fuji on July 12. Crunchyroll is streaming the series as it airs.

The main cast includes Rina Hidaka as Yume Irido and Hiro Shimono as Mizuto Irido. Other cast members include Ikumi Hasegawa as Akatsuki Minami, Nobuhiko Okamoto as Kogure Kawanami, and Miyu Tomita as Isana Higashira.

Shinsuke Yanagi (Bottom-tier Character Tomozaki) is directing the anime at project No.9. Deko Akao (Komi Can't Communicate) is overseeing and writing the series scripts. Katsuyuki Sato (Fire in His Fingertips -My Childhood Friend is a Fireman-) is designing the characters. Yayoi Tateishi is the sound director, while Bit Groove Production is the sound producer. Hiromi Mizutani (Non Non Biyori, Hell Girl) is composing the music, and Pony Canyon and APDREAM are the music producers.

DIALOGUE+ performs the anime's opening theme song "Deneb to Spica" (Deneb and Spica).

J-Novel Club licensed the light novel series, and it describes the story:

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.

Kamishiro began serializing the story on the Kakuyomu website in August 2017. Kadokawa began publishing the story in print volumes with illustrations by Takayaki (Arifureta - From Commonplace to World's Strongest) in December 2018. Rei Kusakabe launched a manga adaptation of the novels on Kadokawa's ComicWalker website in December 2019.

Sources: My Stepmom's Daughter Is My Ex anime's Twitter account, Mainichi Shimbun's Mantan Web