Shinkai no Kantai: Submarine 707 — Episode 1

A mysterious object attacks and destroys any ship or submarine. Submarine 707 has the mission to search for that mysterious object, when summoned by a whale to follow it. The whale leads them to the world of Mu. But on their way they meet the mysterious object. They find out , it is Commander Red Silver, who had attacked the world of Mu to get Mu's magma sources. Submarine takes up the battle to defeat Red Silver and