Mitsurugi proved himself as a soldier at Noshima Island, the main headquarters of the Mori Clan's Maurakami Navy. REspected by his superiors, Mitsurugi was entrusted with the task of defeating Takamatsu Castle at the front lines of the Mori Army.

Takamatsu Castle was considered difficult to conquer because it was surrounded by marshlands. However, a cunning enemy of the Mori named Toyotomi Hideyoshi invaded the castle by flooding the area. Toyotomi constructed a levee around Takamatsu Castle and then released the river water from the rain-swollen Ashimori River, neutralizing the natural defense offered by the marshlands.

Both sides continue to engage in battles that end in stalemate. As the fighting rages on, Mitsurugi boards a raft to join his comrades on a battlefield with arrow-filled skies.