Kanna had retired from her work as an investigator and was spending peaceful days in her family's countryside home, healing from the wounds of her battles. However, that tranquility is suddenly snatched away. Kanna is attacked by multiple assassins and her life is put in danger. Despite being out of practice, she somehow manages to fight back and successfully subdue her assailants, but the identities hidden beneath their masks were those of her former comrades. A shaken Kanna fails to notice the attacker behind her and is knocked unconscious. When she awakens, she is imprisoned, unable to move... A vengeful lesbian training session, born of grudge and mixing love and hate, is about to begin.