In the neon-drenched capital of Yamato, where lights are overshadowed by darkness, a covert armed force known as "Kaika" is deployed to handle major incidents within the city. When facing criminal organizations or terrorists that the police fall short to handle, especially those threatening national facilities or plotting to assassinate key figures and royalty, Kaika is tasked with executing armed clean-up operations. Silent and deadly. The Haboku of the Kaika forces possess exceptional close combat skills, combining ancient techniques with advanced technology during combat. Wielding blades that are both mesmerizing and lethal, they slice through enemy armor as easily as cutting silk. They are the blades in the dark, the silent assassins who bring conflicts to an end. Where they tread, only silence remains…