The Japanese SDF ship Mirai sets sail towards Hawaii to participate in a joint exercise with the US Navy, but encounters a strange meteorological anomaly in the vicinity of the historical battle of Midway.
The Mirai suddenly finds herself in the middle of the Combined Fleet formation of the night before the Battle of Midway. The crew must react to their new circumstances and decide on a new course of action from their original mission.
Kadomatsu rescues an Imperial Japanese Navy officer, Lt. Commander Kusaka, from a sinking seaplane. The Mirai's crew fear that they may have already, or will, change history. The Mirai is discovered by an American submarine, USS Guardfish.
