Nanjo Sayaka enters an eighteen-month servitude contract to cover her family’s debt and spends 300 days confined by a wealthy man. Her life becomes a cycle of eating, sleeping, and relentless sex as repeated conditioning turns her into his obedient plaything. Day after day she is driven into incontinence, convulsions, and endless orgasms until pleasure completely conquers her resistance and she submits to a life devoted to his cock.