Betrothed to My Sister’s Ex Anime Announces July 4 Premiere and New Cast
Betrothed to My Sister’s Ex anime premieres July 4, 2025, with new cast and themes.
The anime version of Betrothed to My Sister’s Ex, which is based on Tobirano’s light novel series, will begin airing on July 4, 2025. The announcement of the air date was made available at the same time as the second promotional video, which included new cast, a second key visual, and theme song and artist information. The series will air late at night on MBS, TBS, and CBC, with a subsequent broadcast on BS-TBS.
The opening theme song, titled "Gesshoku" (Lunar Eclipse), is performed by krage, while Myuk performs the ending theme, "Marie." Both songs were previewed in the promotional videos released by the official website.
Expanded Cast and Production Team
New cast additions include Minami Tanaka as Anastasia, the eldest daughter of Baron Shederan and Marie’s older sister; Ryōhei Kimura as Louisphon, Kyuros’ school friend and third prince of the Diltz Kingdom; Yōko Hikasa as Mio, head maid and guard at Kyuros’ estate; and Sayaka Ōhara as Ryu-Ryu, Kyuros’ mother. The leads are played by Rena Motomura as Marie and Daiki Hamano as Kyuros.
The series is directed by Takayuki Kitagawa at LandQ Studios, with Masakazu Sunagawa assisting. Kenta Ihara is responsible for writing and overseeing scripts. Akiko Satō is designing the characters, and Kujira Yumemi composes the music.
Background and Story
Betrothed to My Sister’s Ex originated as a web novel on Shōsetsuka ni Narō in October 2019. The light novel series, illustrated by Mai Murasaki, began publication in April 2020, with eight volumes released to date. A manga adaptation by Chikage Nakakura started in 2020 on Futabasha’s Gaugau Monster website and currently has eight compiled volumes. An official English manga version is available on Comico’s Pocket Comics platform but has not been updated since November 2023.
Seven Seas Entertainment licensed both the light novel and manga for English release, with plans to begin distribution in January 2026.
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The story centers on Marie, who has lived overshadowed by her sister in a poor baron’s household. When her sister dies just before marrying a wealthy Earl, Marie is set to take her place. However, a serious misunderstanding about the engagement leads to unexpected complications as Marie tries to win the Earl’s heart and find a better life.
Written By Manika Kayal, Intern, India Today Gaming.
