The first half of the story takes place at a high school in Japan, which is the best school in the city where the story takes place. This high school is largely modeled after the University of Tsukuba-affiliated junior-high and high school Komaba in Setagaya, Tokyo, Japan. Throughout the story, glimpses into an Illusionary World are shown. This world is devoid of all life except for a young girl, though she later makes a body out of junk pieces through which the player can interact with her. The remaining half of the story takes place in the same city, albeit ten years after the conclusion of the first half.
There are recurring themes that appear throughout the story. The main theme is the value of having a family, as the title of the series implies since according to Jun Maeda, Clannad mistakingly means "family" or "clan" in Irish.[1] Of the six main characters, Tomoya, Nagisa, and Kotomi have no siblings. The minor theme of Irish words continues with the opening theme of the game, "Mag Mell", which means roughly "plain of joy" and is connected with Irish mythology. The arrange album, a short music CD that contained remixed versions of songs in the game, that was released with the original game release was entitled Mabinogi which was a collection of prose stories from medieval Welsh manuscripts; Welsh is a branch of Celtic, as is Irish.