The upcoming anime adaptation of “Betrothed to My Sister’s Ex” has revealed three new cast members, adding more depth to the romantic and dramatic entanglements of the series. This announcement comes alongside a new trailer and key visual, building anticipation for the show’s premiere on July 4, 2025.
What “Betrothed to My Sister’s Ex” Is All About
“Betrothed to My Sister’s Ex” tells the story of Marie, the neglected younger daughter of Baron Shederan. Treated more like a servant than a family member, Marie lives in the shadow of her older sister, Anastasia. One fateful day, she meets Count Kyuros Granado, a wealthy and initially misogynistic nobleman, who falls in love with her at first sight. However, due to a misunderstanding, Kyuros proposes to Anastasia instead. Tragedy strikes when Anastasia dies in a carriage accident, leading Marie to take her sister’s place as Kyuros’s fiancée under pressure from her family.
As Marie navigates this complicated situation, she grapples with feelings of inadequacy and the belief that Kyuros truly loved Anastasia. Meanwhile, Kyuros is determined to show Marie that she is the one he desires.
Exciting New Cast Announcements
The latest announcements reveal the voice actors behind three key characters:
- Minami Tanaka as Anastasia: Anastasia is Marie’s beautiful and cherished older sister, who initially receives Count Granado’s proposal.
- Ryohei Kimura as Louisphon: Louisphon is Kyuros’s school friend and the third prince of the Diltz Kingdom.
- Yoko Hikasa as Mio: Mio is the head maid and a guard at Kyuros’s estate.
- Sayaka Ohara as Ryu-Ryu: Ryu-Ryu is Kyuros’s mother.
These additions join the previously announced cast:
- Rena Motomura as Marie: The downtrodden but kind-hearted protagonist.
- Daiki Hamano as Kyuros: The wealthy count who finds himself in a complicated love triangle.
Production Details
“Betrothed to My Sister’s Ex” is being directed by Takayuki Kitagawa at LandQ Studios, with Masakazu Sunagawa as assistant director. Kenta Ihara is handling the series composition and scriptwriting, while Akiko Sato is in charge of character design. The music is composed by Kujira Yumemi.
Theme Songs
The opening theme song, “Gesshoku” (Lunar Eclipse), is performed by Krage, and the ending theme song, “Marie,” is performed by Myuk.
From Web Novel to Anime
“Betrothed to My Sister’s Ex” began as a web novel on Shōsetsuka ni Narō in October 2019. The light novel series, written by Tobirano and illustrated by Mai Murasaki, started publication in April 2020. A manga adaptation by Chikage Nakakura launched in 2020 on Futabasha’s Gaugau Monster website. Seven Seas Entertainment has licensed both the light novel and manga for English release, with plans to begin distribution in January 2026.
With a blend of romance, drama, and a Cinderella-esque storyline, “Betrothed to My Sister’s Ex” is shaping up to be a must-watch anime of the summer 2025 season.
