Kaitei 3-man Mile (Movie, 1 episodes, AniDB)

Requested on Oct. 25, 2019, 8:33 p.m.

Returning home from an ocean trip, young Isamu meets the beautiful sea-dweller Angel on a volcanic island. Attacked by a fiery dragon, Isamu and Angel escape on the observation boat See Through, and Angel invites Isamu to see her undersea kingdom of Atlas.