Her Japanese name comes from the English word "Beauty" while her English name, Rosy, comes from the rose flower because her suit and hair color is red.
She is a lazy hamster with a warm heart. She is the most moderate and relaxed out of the Rainbow Girls, but this doesn't always apply when Prince Bo is around. She admired how the Ham-Hams saved the pirates' ship that was going to fall in the sea while the other girls continued to selfishly slander the Ham-Hams. She is always in her best act when Bo is around, but this doesn't stop her from fighting with the other girls.