Amu-chan ends up staying at her older brother's house. Not wanting to tell him about her frequent urination and tendency to wet herself, she confides in his wife, Chiharu. Kind-hearted Chiharu devises a plan to prepare a large supply of disposable diapers for Amu to wear during her stay. Though embarrassed about wearing diapers again despite being grown up, Amu gradually feels at ease. During the evening bath, Chiharu gently helps her put on the diaper, allowing Amu to relax and sleep peacefully. The story captures Amu's special night filled with warmth and tenderness.