The older sister is an elegant female doctor, and the younger sister is a polite nurse. For some strange reason, they keep encountering a man who constantly exposes his rock-hard ch○ck, known as the "erection-showcasing guy." To protect her sister, the older sister repeatedly uses her fingers and tongue to handle the man's ch○ck, helping them get through each crisis. Meanwhile, the younger sister gets extremely excited whenever she sees a stiff ch○ck and can't help but give oral service. Today, the sisters might once again be intently licking or staring at some stranger's or patient's ch○ck!