Set in a high school located in some Japanese town. Okazaki Tomoya is a third-year student who does not take his studies seriously. Always late for class, he is seen as a delinquent by the rest of his classmates who are busy preparing for their college entrance examinations. Needless to say, he does not have too many close friends either.

Tomoya does not seem not to mind either — until one day he meets a girl, Furukawa Nagisa, who is left alone without friends in the school because everybody she knew already graduated. "What a clumsy girl", he thinks at first. But he can not leave her alone and so, while helping her, he meets a few other girls from his school. Although he does not care much about them at first, he soon opens his heart to them as they get to know each other better.