Hibiya Chitose is Hideki's karinrin or apartment manager. She is very sincere, sweet, and understanding, even offering to help out Hideki by giving Chii clothes to wear because he didn't have enough money to buy her anything. However, behind Hibiya-san's composed face, she hides a secret that is crucial to the relationship of Hideki and Chii. A secret and a memory that Chii had lost a long time ago. Hibiya-san is very motherly towards Chii and she wishes for her to be happy and to find that someone just for her. Hibiya's secret and past comes to life during the end of the anime and the manga. Hideki eventually finds out that she had been the one writing those books that Chii reads. But why? Why does she know so much about Chii? As the series went along, the answer to this is obvious. And again, it just all comes down to love and acceptance. It all comes down to Hideki's character and what he belives in his heart. I think Hibiya knew from the very beginning, that though Hideki is certainly not a perfect guy, he really was the only one to end those painful memories of the past. Both for her and for Chii's.