The series follows the unfortunate Kouta, a young man who accidentally summons Luluna, a petite, child-like succubus with an insatiable appetite for life essence. Bound by a demonic contract, Kouta becomes her unwilling 'shimobe' or servant, forced to provide her with a constant supply of sexual energy to survive. The entire series arc is a chronicle of their escalating sexual encounters. Initially, Kouta is overwhelmed by the demanding and lewd Luluna, who relentlessly milks his cock dry with her tight little mouth and wet pussy. Each episode introduces a new depraved scenario, from public blowjobs to intense creampie sessions where Kouta is commanded to fill her tiny, fertile womb with his hot seed over and over. As the story progresses, their dynamic shifts; what starts as forced servitude blossoms into a twisted, co-dependent relationship fueled by raw lust. Kouta finds himself developing a perverse affection for his demonic master, eagerly anticipating the moments he gets to fuck her small body senseless, exploring every inch of her, from her dripping cunt to her tight asshole, while she drains him of every last drop of his potent cum.