Amu-chan visits her older brother's house. Deeply in love with him, she's terrified of him discovering her chronic frequent urination and incontinence issues. Seeking help, she confides in her brother's wife, Chiharu. Kind and compassionate, Chiharu buys a large supply of disposable diapers and devises a plan for Amu to wear them during her stay. The next day, Chiharu purchases even more cloth diapers, delighting in padding Amu's cute bottom until it's plump and puffy. Amu wets her first cloth diaper and receives care from Chiharu, experiencing a warm, familial bond as she's tenderly looked after.