Kuromi is the main antagonist in the series. She works with Baku. Her rival is My Melody. In the final episode of Kuru Kuru Shuffle, when My Melo told everyone that she will lock herself in a cabinet, Kuromi told My Melo that if My Melo dies, who will she fight?
Kuromi wears a black hood with a pink skull on her hood. Around her neck area, are jester points sticking out of her hood. She has white fur, a pink nose, and has eyelashes.
In her youth, Kuromi was actually as friendly as My Melody. After (accidentally) ripping out her notebook to clean Piano's nose, and other things that Kuromi thinks My Melody did to her just to ruin her life, her personality became a drastic change. She became more arrogant, mischievous, and cruel (even Baku agrees!). Despite this, she has a soft spot for cute guys, such as Keiichi Hiiragi and Prince Sorara. Also, she seems to care about her family and her rival, despite the mishaps that happened to her.