The official website for the live-action adaptation project based on Kaiji Kawaguchi's political-military manga The Silent Service announced today that its second theatrical film is set to release in Japan on September 26, 2025 . The subtitle for the second movie is "Hokkyokukai Daikaisen," which is translated to "The Great Sea Battle of The Arctic Ocean." On the website, a teaser visual — depicting Yamato diving into the deep sea between the icebergs with the Northern Lights in the sky — and a behind-the-scenes clip showing the filming that took place from August to October were also released. Kawaguchi's original manga was serialized in Kodansha's Weekly Morning magazine from 1988 to 1996, then compiled in 32 tankobon volumes with a total circulation of 32 million copies (paper and digital). As Amazon Studios' first Japanese theatrical film, the first live-action project's feature film released in Japan on September 29, 2023, earning 1.37 billion yen (9.02 million Usd) from its total domestic run.