|Series||Hi Hi Puffy AmiYumi|
|Nano Item||Spike Dog Collar|
|Voiced by||Grey DeLisle|
|“||Is that the best you got, you slime freaks?!||”|
Yumi is a fifteen-year-old rock star who has blue eyes, purple hair, and a fair amount of Goth style. She wears a spiked leather dog-collar and a studded bracelet; she also wears a light purple T-shirt with a skull on it (which oddly changes its facial expressions to match hers). She also wears a black miniskirt with purple bike shorts and black army boots. Her best friend is Ami; her favorite kind of music is heavy metal. Since Yumi is younger than Ami, she is more headstrong, though Yumi is also more mature than Ami ― usually.
One day Yumi and Ami were going to their favorite dance club, Dance Dance World, but it was closed. Ami suggested to Yumi that they should open their own dance club, that would never be closed when they wanted to dance. Though at first reluctant, Yumi eventually agreed and actually did most of the work building it. Ami named the place "Disco Land" without even consulting Yumi; in fact, the only thing Ami let Yumi have her way on was the rule that non-Cartoon Network characters would not be allowed access.
Fusions have broken into Disco Land, but Ami doesn't fight them. She just dances leaving Yumi to fight alone. Yumi has complained that Ami is being selfish, but won't tell confront her about it, so as not to threaten their friendship and make Ami cry.