The "dark knight", Ingrid works for the crime organization, Nomad. The leader of the company, Edward Black, grows suspicious of Nomad member, Kiryuu Sabato who has recently captured renowned taimanin, Murasaki. However, the investigation was all part of Sabato's plan, as Ingrid falls into his trap is captured. Sabato reveals he is planning to use Ingrid as bait for Edward, and while waiting for him, he also intends to break the spirit of Ingrid and Murasaki. Hence, Ingrid finds herself serving as a sex slave alongside her former foe, hoping to retain her sanity until her rescuer arrives.