Yuko has been troubled recently about her younger brother buying a cup for masturbation because handa alone isn't enough anymore.
Her younger brother was under so much pressure from preparing for the college entrance exam that he had to masturbate every day to relieve stress.
I don’t know why the masturbation cup broke so quickly that I bought several, and one day she caught me red-handed!
As for her younger brother who can't study because of too much pressure, Yuko, who has been raised by her mother since childhood, came up with a solution: use herself as her younger brother's masturbation cup!