Atashi is the main character in the books Chii reads. Atashi, though its name is never said, is the pink bunny who represents Chii. These "mysterious" books Chii reads called "A City with No People" were actually written by Chitose Hibiya, who is referred as Chii's "mother". When Chii reads these books, she feels pain in her "heart", In which case, Freya tells Chii these stories are of her past and present times.

In book 4 of the manga, Hideki notices that these books are actually telling the story of him and Chii. At first Hideki thought these were just drastic picture books, but as he reads them he learns a lot about Chii and the mystery of her.

Atashi speaks in a very simple way, like a child, and all she does is looks around the empty city, peaking through the windows, looking for the "someone just for me". She refers the persocoms as "them", but if you notice Atashi is the only one different, meaning Chii is different from the other persocoms.