Moments after an atomic bomb falls over Hiroshima, a secret Japanese submarine sails into battle against its American counterpart, and both are lost to history. Some fifty years later, a special UN task force sent to investigate unusual phenomena in Antarctica is threatened by a mysterious black cylinder.
Before I saw Blue Submarine No. 6. I remember watching a very similar anime. The basic similarity was in that both shows feature prominently an indefeatable battleship, and an equally indefatigable crew. However, Shin Kaitei Gunkan is different in that it is significantly older, and other historical themes play a more important role. For example, the titular submarine, is a symbol of Japanese nationalism during World War II, in the same way, that the antagonist's battleship, the Liberty, is an expression of perceived American imperialism. In any case, despite these strong echoes from the past, it is a highly enjoyable
experience, although one that is short-lived, and inconclusive, leading one to wonder whether the conflict with the Mu was resolved at all.