The highly anticipated television anime adaptation of Kōcha Agasawa’s popular web manga, Koori no Jyōheki (The Ramparts of Ice), has unveiled its main cast, key staff, and an April 2026 premiere date. The announcement was made alongside a new visual and a teaser promotional video, confirming that Studio KAI will be animating the series.
Unveiling the Main Cast and Their Roles
The anime features a talented ensemble bringing the four central characters to life. Anna Nagase, known for her diverse roles, will voice the protagonist Koyuki Hikawa, a high school student often perceived as unapproachable due to her reserved nature.
The main cast includes:
- Koyuki Hikawa: Voiced by Anna Nagase
- Miki Azumi: Voiced by Fūka Izumi
- Minato Amamiya: Voiced by Shōya Chiba
- Yota Hino: Voiced by Satoshi Inomata
These actors will portray the complex relationships and emotional journeys of the four somewhat complicated individuals at the heart of the story.
Key Staff Bringing the Manga to Life at Studio KAI
Studio KAI, recognized for its animation work on various titles, is set to produce “The Ramparts of Ice.” The production team includes:
- Director: Mankyū (known for Pui Pui Molcar the Movie: MOLMAX and The IDOLM@STER Shiny Colors)
- Series Composer: Yasuhiro Nakanishi (Kaguya-sama: Love is War, Toilet-Bound Hanako-kun)
- Character Designer: Miki Ogino
- Music Composers: Kanade Sakuma and Natsumi Tabuchi
This experienced staff aims to faithfully adapt Agasawa’s beloved story to the screen, capturing the nuances of the characters and their development.
The Story of The Ramparts of Ice
The Ramparts of Ice (Japanese: Koori no Jyōheki), originally a webtoon by Kōcha Agasawa, follows Koyuki Hikawa, an aloof high school student who struggles to connect with others, often building an emotional wall around herself. Despite her solitary demeanor, a friendly classmate named Minato Amemiya persistently tries to get closer to her. The narrative delves into the frustrating yet poignant story of youth, exploring the lives of Koyuki, Minato, the popular Miki, and the laid-back Yota as they navigate high school and forge unexpected friendships.
The manga gained significant recognition, including ranking #15 for male readers in Takarajimasha’s Kono Manga ga Sugoi! 2024 guidebook and being nominated for the 69th Shogakukan Manga Awards in 2023. It also secured the second spot on AnimeJapan’s sixth “Most Wanted Anime Adaptation” poll in 2023, highlighting the strong desire among fans for an animated version.
Manga’s Serialization and Publication
Kōcha Agasawa first self-published The Ramparts of Ice as a webtoon before it was serialized on the LINE Manga app from January 2020 to April 2022. Shueisha later published the manga in fourteen compiled tankōbon volumes, with the final volume released on February 4, 2025.
Fans can look forward to the anime’s debut in April 2026 on TBS and other channels, bringing this popular coming-of-age story to a broader audience.
