Kururin-chan

Owned by Glitter. Sparkle is a spoiled pop star hamster. She did not like the Ham-Hams at first, but she gradually became attached to them. In the Japanese episodes, Sparkle began to have a crush on Hamtaro and has since then been trying to get him to notice her. She was unsuccessful, so after that, she tried to push Hamtaro and Bijou together, but her feelings for Hamtaro came back again.

She is also quite selfish, for example when the Ham-Hams were talking about her, but then changed the subject, she says, "I'd like to talk about me again!". Sparkle believes she is the cutest hamster in the world. She has her own albums as her owner takes her everywhere. After she gets attached to the Ham-Hams, she's shown to be kind on the inside, and cares for Bijou like a best friend, and gets annoyed at Oshare's oblivious and childish nature. She races against Bijou and Oshare to win Hamtaro's heart in A Valentine Battle! but ultimately helps them finish the race with her.

(Source: Hamtaro Wikia)