High schooler Kei Tsuchiya joins The Destroyers when she decides that her longtime karate master is holding her back. She realizes her mistake but it's too late.

In Okinawa, Ayaka Kurenai was born in the world’s greatest legendary Karate family. When she was a child, her family was attacked by a mysterious gang that seeks legendary black belt. Her father Soujiro Kurenai was killed and her younger sister was taken in front of her. Time has passed. In Yokohama, she was spending her life as a normal high school girl, hiding her real name and her status as a heir of the legendary Karate family. However, one incident brought her a fateful encounter with her sister who was separated in their childhood. But, her sister was raised as a heartless killing machine by the mysterious gang who took her. .

Mai is a member of the Salvage Mice, a pair of thieves who return stolen treasures to their original owners. Mai is betrayed by her former partner to a gang of thieves. She sets out on a path to restore the reputation of the Salvage Mice name and bring her partner's new gang to justice.