Newly hired caregiver Yuria's first assignment is elderly man Ippei, who lives with his daughter Masako. Ippei constantly complains, demanding to see grandchildren soon, which only earns him a stern attitude from Masako. Between this father and daughter lies a deep-seated conflict. Learning of their strained relationship, kind-hearted Yuria offers, "If you'll have me, I can be your granddaughter." But Masako begins to watch Yuria with complex, twisted eyes. Eventually, Yuria accidentally breaks Ippei's glasses. Enraged, Ippei punishes her with spanking and cunnilingus. Masako's schemes don't end there—Yuria gradually finds herself subjected to more of Ippei's sexual punishments, slowly awakening her own sexuality.