Persocons have transformed into "Persocoms" in the far-off future, becoming mobile devices that appear human-like. Although Hideki Motosuwa, a high school student, is keen to own one, the cost of purchasing a Persocon is beyond his reach. However, luck seems to be on his side when he stumbles across an abandoned Persocom and decides to take it in. Upon activation, the device only makes a sound of "Chii," leading Hideki to dub it with the same name. As time progresses, it becomes evident that Chii is not your typical Persocom, as she boasts extraordinary capabilities and the potential for independent thought, indicating she may be a coveted "Chobit" model.