Nephew spends a week staying at his sick aunt's (Yukari Matsuzawa) house to care for her. On the first day, he's asked to help with simple tasks like changing her diaper and tending to her underwear. During this, he becomes aroused and unintentionally gets an erection. Seeing her nephew in this state, the aunt mischievously tells him, "Why don't you try drinking my pee?" and forces him to drink her urine. Witnessing his shocked and reluctant obedience, a special emotion begins to stir within her. From then on, as a reward for drinking her urine, she gives him ultimate blowjobs, lets him lick her unwashed pussy, makes him lick her anus—introducing him to one of his firsts after another. Through daily caregiving, their bond gradually deepens. But just as the nephew realizes "my aunt's piss tastes delicious," the time for them to part ways draws near...