Narutaru: Mukuro Naru Hoshi Tama Taru Ko
English name: Shadow Star Narutaru
Genres: Drama, Suspense
Type: TV, Episodes: 13
Aired: Jul 7, 2003 to Sep 29, 2003
Studio: Planet
Source: Manga
Rating: R - 17+ (violence & profanity)
Synopsis:
During her summer holiday at her grandparents house Tamai Shiina, a young and cheerful schoolgirl, meets a strange looking creature. They befriend each other and Shiina names it "Hoshimaru: The Round Star." When Shiina returns home after the summer to go back to school, she starts meeting other kids that also have befriended a strange creature like Hoshimaru. But she soon finds out that not all these creatures and their masters are as friendly as Hoshimaru.

(Source: ANN)