The Japanese Navy's newest and most advanced warship, the Mirai, is on a routine training exercise when it is suddenly transported back in time to June 4th, 1942, the day of the pivotal Battle of Midway. Commander Kadomatsu and his crew find themselves in the midst of a pivotal moment in history, where the Japanese fleet suffered a devastating defeat. Despite their initial intentions to avoid interfering with the course of events, the crew is drawn into a confrontation with a U.S. submarine that should not have been there. As they fight for their lives, they inadvertently alter the course of history, setting off a chain of events that could forever change the outcome of World War II.