In the future, personal computers have developed into "Persocons", mobile computers that are barely distinguishable from normal people.
Enter Motosuwa Hideki, a teenager who's come to Tokyo for prep school. Fresh off the farm, he's surprised and awed by the Persocons, which appear everywhere in Japan. Being the guy he is, he realizes he can never have one because of his lack of money. But luck is with Hideki when he finds a Persocon in the trash. Hoping to salvage it, he brings it home with him.
With the help of a newly found school friend Shinbo, he is able to get her up and running. However, it appears as if she may indeed be broken! Though only able to say Chii, he's immediately gladdened by her obvious affection towards him. But what of her original owners? Why was she in the trash to begin with? Could it be that she is the remnants of an experiment that sought to create an artificially intelligent being? Could she be, in fact, a CHOBITS?