In a futuristic Shanghai, humans and sea creatures live in fragile symbiosis. Shy ship engineer Stefan is struggling to make his way through a merciless corporate hierarchy that ignores his visionary ideas. But everything changes the moment he's unexpectedly asked for his hand in marriage by princess ChaO, daughter of the ruler of the seas himself, King Neptune. The pair suddenly find themselves at the center of media attention, swept up in a whirlwind of emotions on a wild journey to discover mutual closeness, intimacy, and self-acceptance.

The story of two worlds coming together is told through an interview a young journalist from the near future conducts with Stefan, in which he explains how his surprising union with ChaO came about.

Visually unrestrained and playfully witty, this anime by director Yasuhiro Aoki celebrated success at the Fantasia and Sitges festivals and was crowned with the Jury Award at the prestigious Annecy International Animated Film Festival.

Director: Yasuhiro Aoki
Screenplay: Kino Hanasaki
Cinematography: Takanori Nakashima
Music: Takatsugu Muramatsu
Editing: Kengo Shigemura
Country of origin: Japan
Year of production: 2025
Runtime: 90 min.