Rosa is the girlfriend of Go from Rave Master, she fights Elie thinking that she is the Rave Master, when Haru is.
Rosa is a movie actress like her boyfriend, Go. When using a machine to create a never ending rain on a town, she unknowingly causes the town to suffer due to the movie they are creating.
According to Hiro Mashima, Rosa is created to fight Elie. Rosa is a minor character who only appears during the Dancing Thunder Arc. Her first appearance in the anime series is Rave Master: Episode # 11. and volume 4. Rosa is voiced by Japanese actress, Miki Nagasawa, and by English actress, Dorothy Elias-Fahn.
Rosa makes her first appearance after Go has collapsed and fall unconscious due to Haru's Explosion attack. Before Rosa decides to challenge the Rave Master, she turns up the music. Her music causes all boys to dance (Interestingly, Plue dances on his free will). She mistakenly thinks Elie is the Rave Master, and the two fight. Rosa is the first one to hit Elie in the stomach, but she gets smack
in the stomach after Elie gets some retribution. After getting punched in the stomach, Rosa decides to use her chain sword as a whip. She unleashes her "Dancing Wolf" attack on Elie. However, Elie shoots Rosa's chain sword and the music which causes Rosa's chain sword to go out of control. When Rosa gives up and cries out for help, Elie helps Rosa by grabbing the chain sword and stopping it for good. Rosa listens Elie's points about having a pretty face. Rosa decides to wake up Go to stop the Rain, but Go unconsciously punches Rosa in the face. Rosa gets knock out. After Haru and Go fight each other which ends in Go's defeat at the hands of Haru with Plue's help, Rosa wakes up. She beats Go for hurting her face, and she makes him turn off the rain. However, Go does not remember how to turn off the machine, but Plue saves the day by pressing the right button. After Haru and his gang leaves, Rosa talks to Go about finishing the movie. During the end of the Dancing Thunder arc, Go talks to Rosa about restoring the town.
Rosa has a chain sword and her attacks are Dancing Wolf.