On the Beach: In a summer in Shonan village, Sumiko is the daughter of an important upper-class Shikishima family, she loves to paint pictures, is going through a cooling-off of an arranged marriage that did not work out. However, she feels attraction for Nishina a rough and obscene man ... On the other hand, the younger sister, Naomi Sumiko is envious of her sister for her beauty. Naomi feels ugly since all men seem to like Sumiko. Both sisters then become embroiled in a major problem in discovering the real intentions of Nishina, a man who hides behind a mask to rape women.