Clannad

Okazaki Tomova is a third-year student at a high school somewhere in Japan, and 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.

Tomoya does not seem to mind though — until one day he meets a girl, Furukawa Nagisa, who is left alone without friends at school because everybody she knew already graduated. "What a clumsy girl", he thinks at first. But talking to her feels natural 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 as they get to know each other better.

(Source AniDB)