Wakamatsu Masato lives with his step-sister, Miyuki, with whom he shares no blood relation. Their father is constantly working overseas and has left the two of them to live alone in Tokyo. Miyuki is cute, kind, sensitive, and very popular with the boys around Masato. Masato has a girlfriend at school named Kajima Miyuki, who is pretty and gentle, representing the ideal dream of every high school boy.