学園聖戦士セーラーナイト2 ～正義のヒロイン完全悪堕ちマニュアル～

Present day Japan: Unknown lifeforms called "Mouma" appear.

Conventional weaponry is useless against them; the only countermeasure available is the "Sailor Knight", female warriors of justice protected by holy gemstones.

An ordinary student, Utsuroi Hayata, awakens as the "King of the Mouma" with the power to manipulate illusions.

His terrifying brainwashing through sexual pleasure eventually compels "Sailor Star Ruby" to swear absolute allegiance to him, becoming "Sailor Mouma Princess".