In Demon City Tokyo, the loyal Dark Knight Ingrid captures an Anti-Demon Ninja to serve her master, Black-sama. However, amidst internal power struggles and betrayal, Ingrid is lured into a treacherous ambush where she is incapacitated by a potent aphrodisiac and subjected to the cruel whims of her enemies.
Ingrid's pursuit of the traitor Kiryuu Sabat ends in disaster when she is captured and subjected to sadistic sexual torture and aphrodisiacs. Kiryuu also lures and breaks another aide, Murasaki, before hosting a depraved gathering where he publicly humiliates Ingrid to shatter her pride. Despite the relentless abuse and degradation, the defiant Dark Knight refuses to submit and vows to destroy Kiryuu.
After capturing the ninja Murasaki and the Dark Knight Ingrid, Kiryuu subjects them to biological modifications that grant him total control over their bodies and drastically heighten their sexual sensitivity. To avoid betraying her master, Edwin Black, Ingrid agrees to a degrading pact to service one hundred men in exchange for the right to die. Both women are subsequently forced into a public brothel, where they are humiliated as slaves for Kiryuu's demonic clientele.
Kiryuu subjects Ingrid and Murasaki to extreme humiliation and slavery while unveiling Nabelius, a bioweapon engineered from Edwin Black's DNA. However, Black lures Kiryuu into a trap and easily defeats the creature. With her freedom restored, Ingrid obeys Black's command and obliterates Kiryuu, bringing a violent end to his reign of terror.