Clannad follows the life of Tomoya Okazaki, a high school delinquent who meets many people in his last year at school, including five girls, and helps resolve their individual problems.

The gameplay of Clannad follows a branching plot line which offers pre-determined scenarios with courses of interaction, and focuses on the appeal of the five female main characters by the player character. The game was ranked as the best-selling PC game sold in Japan for the time of its release, and charted in the national top 50 several more times afterwards.