Born to an outlaw yakuza boss, Kei Enjoji becomes fascinated with Ranmaru Samejima, a gifted kendo fighter. Kei desires an honest, selfless level of intimacy with Ranmaru that ultimately transforms into a deep romantic love. After thwarting a brutal assault on Kei by yakuza members, Ranmaru renounces kendo forever, leaving them to rely solely on each other. They opt to distance themselves from the yakuza nexus and begin a new life together as a couple. Nevertheless, their happiness is interrupted when an unfamiliar face arrives, hunting for Ranmaru. They are unwillingly forced back into the perilous underworld they risked their freedom to flee, and their affection may not endure the looming danger.