Newly graduated caregiver Rei earned the trust of her elderly patient, Kiyoshi, with her sincere and meticulous care. But one day, she dozes off during duty and is harshly confronted by Kiyoshi. The reason? She's been working tirelessly to pay off her fiancé's debts. Learning this, Kiyoshi shows no sympathy—instead, he begins increasingly obsessive sexual harassment. During meals, he forces mouth-to-mouth feeding, entwining his tongue with hers; during sponge baths, he makes her meticulously clean his cock, gradually asserting control over her body. As Rei grows distressed, Kiyoshi calmly hands her hush money. Worried about her future with her fiancé, Rei ultimately enters into a silent physical contract, crossing the line with the old man. The story portrays her emotional turmoil and the painful choices between morality and desire.