Izumi Konata
The very representation of an otaku, Konata (or sometimes called 'Kona-chan') is the childish but good-natured leader of the Lucky Star girls. Usually a lazy girl who is 'occupied' with video or online games, manga, anime, or all of the above. Konata is actually a capable, intelligent, and athletic girl, but does not join any school clubs because of her otaku interests.
Hiiragi Kagami
Kagami is Tsukasa's older fraternal twin sister and is occasionally referred to as "Kagamin". In school, her grades are excellent because she studies very hard. She was even the class president in her first year. She is in a different class than Konata and Tsukasa, but she frequently comes to their class during lunch time to eat with them.
Hiiragi Tsukasa
Tsukasa is the younger fraternal twin sister of Kagami and lives in a six-member family household with her parents. She is in the same class as Konata. While she is not good at studying or sports, she excels in cooking. She is portrayed as the stereotypical friendly, good-natured but clumsy person. She is often portrayed as an airhead who is unreliable and is always compared to her twin sister, who generally does better than her in most areas. It is often implied that Tsukasa is unable to follow the gist of complex conversations.
Takara Miyuki
Miyuki is a young lady from a wealthy family who is beautiful, smart, and well-mannered. She always uses extremely polite Japanese, even when talking with her closest friends. She was the class president for her grade level in her first year, at the same time that she became good friends with Kagami. Now Miyuki is in the same class as Konata and Tsukasa. Miyuki's classmates often rely on her for help with their studies, and she is often shown giving impromptu but highly-detailed, encyclopedic definitions or explanations on diverse and obscure matters.