The story centers on the life of Hideki Motosuwa, a repeat student attempting to qualify for university by studying at Seki prep school in Tokyo. Besides a girlfriend, he dreams of having a persocom: an android used as a personal computer, which is expensive. On his way home one evening, he stumbles across a persocom in the form of a beautiful girl with long hair lying against a pile of trash bags, and he carries her home.

Hideki discovers that his feelings intensify for Chi whether she is a persocom or not, despite other horrible experiences involving persocoms that happened to his friends. Chi becomes aware of her purpose through a picture book series called A City with No People which she finds in a bookstore.
The books speak about many different things involving human and persocom relationships: persocoms and their convenience towards people as friends and lovers, how there are things that they cannot do and questioning whether a relationship between a persocom and a human is …

As the series progresses, Chi begins to have visions of another persocom who is identical to herself, and eventually learns this is Freya, her twin, and that Chi was originally called Elda; after Freya fell in love with her father and creator and had her heart broken (she couldn’t muster the courage to admit her feelings in the anime), her memories were downloaded into Chi, before her system was wiped at her own request.

CHOBITS takes place in a not-too-distant future when personal computers in humanoid form are all the rage. Perpetually broke Hideki can’t afford one, but he is lucky enough to stumble upon a discarded “persocom” lying in the trash while walking home from work one night. Seizing the opportunity, he takes her home and activates her, but she has no memory. He attempts to train her and seeks assistance from a twelve-year old programming genius, who suspects that she may be one of a rumored new model of supercomputer called CHOBITS.