Armpit hair of a defenseless aunt

Yukari has been living alone since her husband died. After a while, they decided to let their nephews, Seiichi and Ryoji, stay as a boarding house, and the house quickly became lively again. However, although her body inevitably feels lonely, she is able to maintain her composure by keeping the armpit hair that her late husband liked. One day, Ryoji came home looking thoughtful. When I visited him, Ryoji told me, ``I can't help but worry about my aunt's armpit hair.'' Yukari is confused by the sudden confession but asks why...