Main characters

The player assumes the role of Tomoya Okazaki, the protagonist of Clannad. Tomoya has been labeled a delinquent; at the beginning of the story, he even expresses hatred toward the city he has lived in all his life where Clannad is set. He is very straightforward in his comments to others and will not hesitate to speak his mind, even if he comes off as rude during such times. Despite this, Tomoya is very loyal to his friends, and has been known to dedicate himself for those around him in need of help or support. He generally has a selfless personality and does not ask much from others in return for what he does for them.

Tomoya meets Nagisa Furukawa, the main heroine of Clannad, at the onset of the story. Nagisa is a soft-spoken girl who has very low self-esteem and self-confidence which causes her to rely on those around her for support. She has developed the strange habit of muttering the names of favorite foods that she plans to eat as a way to motivate herself, such as anpan. Kyou Fujibayashi, another of Clannad's heroines, is a bad-mouthed and aggressive girl well known as a good cook among her friends and family. When angry she does not hesitate to throw a dictionary at people that she often carries around for such purposes. Despite this attitude, she also has a more subdued side, especially towards her younger fraternal twin sister Ryou Fujibayashi.

Tomoya meets a genius girl named Kotomi Ichinose, one day in the school library. She is ranked in the top 10 throughout the whole country in standardized exam results of every subject—she always goes to library to read extra materials, especially books in foreign languages. Kotomi is a very quiet girl with poor social skills and it is quite difficult to communicate with her; Kotomi can even completely ignore someone when reading, even if they make loud disturbances around her. Clannad's fourth heroine is a second-year student named Tomoyo Sakagami who transfers into Tomoya's school. Tomoyo, like Kyou, can be extremely aggressive, and Tomoyo is a very strong fighter, preferring to use kicking over punching, and is very athletic. Although Tomoya is older than her, Tomoyo does not show him respect as a senior student. Tomoyo appears in Key's fifth game, Tomoyo After: It's a Wonderful Life, as the main heroine.

The last heroine in Clannad is a first-year student named Fuko Ibuki who has a distant attitude towards others and, before she met Tomoya, was generally seen alone by herself making wood carvings of starfish with a small knife to give to others as presents. Fuko is extremely enthralled by starfish, or things that are star-shaped, and will often go into short euphoric bouts where her awareness of her surroundings is completely overtaken.