Rozen Maiden: Detective Kun-Kun

Rozen Maiden (ローゼンメイデン, Rōzen Meiden?) is a manga by the group Peach-Pit (the creators of DearS), with an anime series of the same name. The story centers around Sakurada Jun, a young hikikomori boy that finds himself indebted to a living doll by the name of Shinku, a doll of the Rozen Maiden series, who was created by a mysterious but extremely talented dollmaker. The series examines the living habits and personality of each doll that is living with Jun and his sister Nori, as well as the sibling rivalry that they commence to name one doll as "Alice" in order to meet the maker who created them. Jun's sometimes comedic, sometimes dramatic experiences with Shinku--as well as the other six dolls of the Rozen Maiden series--slowly bring him out of his depression and back into the world that he had abandoned.

In TV Asahi's "Top 100 Anime Ranking" polled in 2006, Rozen Maiden was ranked 9th on the list.

Source: Wikipedia