Sumire has spent her twenty years in a waking nightmare. Living with her abusive mother and older sister Ran, she is nothing more than a household servant and an open wallet. Her mother blames her for the disappearance of her father, while Ran insists her younger sister is destined to be alone forever. All the money Sumire earns from her jobs is confiscated, and she is given no rest, forced to complete all the housework without thanks or kindness. Her only solace comes from reading books, dreaming of the romances and normal lives she sees her former classmates living through social media.

The fragile balance of her miserable life shatters when three intimidating men from the yakuza arrive at their door. Ran has accumulated a massive debt, and the young leader of the Shizuki clan has come to collect. As the men threaten to take Ran to work in one of their establishments, a euphemism for sexual slavery, Ran immediately offers up her younger sister instead. To Sumire’s utter despair, her mother readily agrees to the exchange. Seeing the complete resignation and lack of love in Sumire’s eyes, the young leader is struck by something he cannot explain. Instead of following standard procedure, he decides to take the girl with him.

Expecting a life of even deeper suffering, Sumire is confused when the man, Kiriya, treats her with unexpected kindness. Despite his fearsome reputation as the second-in-command, he seems almost tormented by her blank, hopeless gaze. After seeing her dressed to be sent to work at one of his stores, he makes a sudden decision. Instead of forcing her into the expected role, he declares she will not go to the store. He offers her a new position: his exclusive live-in housekeeper. What follows is a clumsy but deeply doting relationship as Kiriya slowly teaches Sumire what it means to be valued and protected, offering her the place in the world she has always been denied.