Starwing Paradox Prequel Film AS ONE Casts JO1 Member Ruki ‌Shiroiwa

The official Twitter/X account for the upcoming Starwing Paradox prequel anime film AS ONE announced that it has cast JO1 boyband member Ruki ‌Shiroiwa as the character Yo. It will be Shiroiwa’s first voice acting role. The anime film is expected to be screened theatrically in Japan on August 22, 2025. 

A special new promotional video and visual have also been released, confirming the addition of the new character. 

Kobun Shizuno (various Detective Conan films, including The Crimson Love Letter and The Darkest Nightmare; Godzilla: Planet of the Monsters co-director) is directing the AS ONE anime film, with Yoshiyuki Sadamoto (Neon Genesis Evangelion, Great Pretender, Nadia: The Secret of Blue Water) as character designer and Ippei Gyobu (Mobile Suit Gundam: The Witch From Mercury Seasons 1-2) as mechanical designer. Kana Matsui, Shatner Nishida (Lupin III: Prison of the Past), and Masaya Honda (Soul Buster) are serving as the film’s scriptwriters, while Honoo and Studio GOONEYS are in charge of the animation production. 

Sadamoto previously worked on the character designs for the game, which was developed by BYKING and Square ENix. The anime scenes in the game were originally produced by Sunrise.

The Starwing Paradox sci-fi arcade game was released in November 2018 and remained active online until October 2021. Its main game mode featured 8v8 “high-speed” battles involving the Air Real mecha. AZ-One is the name for an Air Real pilot.

Comic Natalie describes AS ONE as a prequel that connects to the original game. The main character is an aspiring musician called Yo, who hears a cry for help one day in their mind and becomes enveloped in white light. A robot mechanic called Rako, who is trying to stop massive falling space debris, falls into a coma and meets Yo in their consciousness. During this time, there is an attempt at a ceasefire between two countries from the planet Meguriboshi who have been warring over energy resources.

Sources: AS ONE Official Twitter, Anime News Network