Mirai, an updated Kongou-class Aegis guided missile destroyer, is one of the Japanese Self Defense Force's newest and most sophisticated ships (SDF). Capt. Umezu Saburo and Executive Officer Kadomatsu Yosuke head her crew, which is also one of the newest. Mirai runs into a violent storm one day while doing routine training drills, which throws their navigation systems into chaos. After a few moments of recovery, the crew is shocked to learn that they've been transported back in time to the Battle of Midway, which took place on June 4, 1942, during World War II. By allowing history to take its course for this battle, they manage to avoid experiencing the conflict firsthand and vow to remain anonymous, changing history as little as possible. When the team arrives, though,