On the frigid edge of the Kaigenese Empire, the warriors of Kusanagi Peninsula defend their homeland with powers that rival the sea itself. For fourteen-year-old Mamoru, mastering these legendary skills isn’t just family duty—it’s the key to protecting his home. But when a mysterious outsider shatters Kaigen’s carefully spun illusions of peace, Mamoru realizes he may be racing against time to become the warrior he’s supposed to be.
Meanwhile, his mother Misaki has buried her past as a fighter, focusing instead on being the ideal wife and mother. But with war looming and her son asking questions, her forgotten skills are hard to ignore.
As danger closes in, will the Matsuda family unite to face their true enemy, or destroy each other first?