Due to her parents' overseas assignment, Nao has to take care of her younger brother Tarou. Because of the age difference, she acts more like a parent than a sibling and tends to spoil him a bit. One day, because of Tarou, the soccer club loses in the prefectural tournament. The members decide to shave his head as an act of reflection. Nao stops them, so the members demand that 'the sister should become bald instead' and request her to go bare. For the sake of her cute little brother, Nao offers her alluring body to them...
