PG13 / Japanese / / 1 Hour 43 Minutes
Rimuru Tempest and his companions are on vacation at a private resort. Their peace is shattered by the arrival of Yura, a priestess from the undersea nation of Kaien, who seeks help to save her people. The kingdom of Kaien is being threatened by a mysterious pollution of the Azure Sea and a conspiracy to forcibly awaken the dormant deity. Rimuru and the Tempest executives must dive into the deep sea to uncover the plot and stop an invasion of the surface world.
| Director: Yasuhito Kikuchi |
| Cast: Miho Okasaki, Saori Onishi, Nao Kosaka, Kaho Fujishima, Makoto Furukawa, Takahiro Sakurai, Hisako Kanemoto |
| Release Date: 14 May, 2026 |