Cocoon: One Summer of Girlhood Drops English Trailer Ahead of September 4 North American Theatrical Release

GKIDS has unveiled an English-subtitled trailer for Cocoon: One Summer of Girlhood, the wartime anime feature directed by Yukimitsu Ina at debut studio Sasayuri. The film arrives in North American theaters on September 4, screening in both Japanese with English subtitles and an English dub.

A Wartime Story of Friendship and Loss

Based on Machiko Kyo's manga - originally published by Akita Shoten in 2010 and licensed in English by Viz Media - Cocoon: One Summer of Girlhood follows best friends San and Mayu as they attend a prestigious all-girls school on a warm, tranquil tropical island. When war reaches their shores, the students are ordered to help nurse the wounded in a military hospital hidden inside a cave. As casualties mount and combat intensifies around them, the two friends struggle to find solace in their increasingly fragile lives.

The film has been described as a devastating yet beautiful plea for peace, weaving its anti-war message through the intimate lens of adolescent friendship under extraordinary pressure.

Studio Sasayuri and Its Ghibli Roots

Cocoon marks the debut production from Studio Sasayuri, founded by veteran animator Hitomi Tateno, who serves as animation producer on the film. Tateno built her career at Studio Ghibli, and that pedigree is reflected in the team she has assembled. The production features acclaimed animators Akihiko Yamashita and Shinji Otsuka, both recognized for their contributions to Studio Ghibli titles including Princess Mononoke and The Boy and the Heron, working alongside a wave of emerging talent.

Director Yukimitsu Ina helms his debut feature with the project, while composer Kensuke Ushio - whose credits include A Silent Voice and Chainsaw Man - provides the score. The Japanese voice cast features Hikari Mitsushima as Mayu and Marika Ito as San.

Festival Run Builds Momentum

The film has already begun building an audience through its festival circuit appearances. Cocoon: One Summer of Girlhood premiered at JAPAN CUTS on July 10, 2026, and has also screened at the Fantasia International Film Festival. These early screenings set the stage for the wider theatrical rollout that GKIDS will launch in September.

GKIDS has established itself as a leading distributor of animated features in North America, with a track record of bringing acclaimed Japanese animation to theatrical audiences across the continent. A home video release is also planned following the theatrical window.

What to Expect

With its blend of Ghibli-trained animation talent, a score from one of anime's most sought-after composers, and a wartime narrative rooted in a critically recognized manga, Cocoon: One Summer of Girlhood carries considerable creative weight heading into its North American debut. Audiences can catch the film in theaters starting September 4 in both subtitled and dubbed formats, distributed by GKIDS.