Uka, who stayed overnight at her cousin's house to prepare for exams, nervously wets the bed in the middle of the night. The borrowed pajamas are soaked with urine, and she blushes deeply in shame. Her cousin, a composed nurse, calmly observes the situation and begins emergency treatment. As a remedy for bedwetting, she puts adult diapers on Uka and deliberately makes her leak large amounts of urine into them. Her cousin's skilled hands meticulously check around the urethra with precise, clinical accuracy, yet exude a distinctly perverted aura. Under the pretext of strengthening her anal sphincter muscles, Uka's ass is toyed with, subjecting her to this humiliating training. In truth, her cousin's real desire is to enjoy watching girls wet themselves. Before Uka realizes it, she's fitted with cute paper diapers, treated like a baby, and made to wet herself again while sucking on a baby bottle. Yet amid this humiliation, a strange pleasure begins to stir within her, unsettling her heart. Gradually, Uka starts to feel new excitement and arousal from wearing diapers and deliberately wetting herself...