Kon Katakura seldom attends classes, but on the occasions she does, her conduct is poor and her academic performance is mediocre. When the new homeroom teacher, Kurosawa, arrives, the two soon enter into a relationship quite unlike that of other students. Through various ups and downs, the couple struggles to define their feelings for one another. The only way they can manifest their affection is through passionate sexual intercourse, which they indulge in day and night. Kon moves into her new boyfriend's apartment, shunning her family and classmates, in an attempt to find meaning in their half-hearted and cursory relationship.