Yumi is the second member of the rock band Puffy AmiYumi. She is a guitarist.
She dresses in a rock style with studded necklaces and ankle bracelets, a light purple T-shirt with a (mostly expressive) skull on it, a black miniskirt, and black knee high boots.
For night time, Yumi wears a black or a white sleeved nightgown with a skull in the middle.
For swimwear, Yumi first wears camouflage bikini in the episode "Robo-Pop," but in "Surf's Up" and til the rest of the series Yumi now wears a purple string bikini with half a skull on the bikini top and the other half on the bikini bottom.
For formal wear in "Movie Madness", Yumi wears a black glittery glamorous dress with the same studded choker from her main outfit and wears black opera gloves.
For ninja wear, Yumi wears a black sleeveless ninja outfit and wears a black balaclava.
As a magician assistant, she wore a pink hairband, a gold necklace, a pink tube top, a pink miniskirt and gold pumps.
In "Secret Origin" and the flashback of "Super Zero", as a kid, she wore a black long sleeve shirt, a white flounced skirt, white socks and black Mary Janes shoes.
In the pilot, she had her hair being more purplish-toned and lighter, a dark magenta shirt with the skull having a green outline, slightly darker skin, freckles, a gray-cyan glove (on her right hand), spiked bracelet (on her left hand) and spiked collar, light bluish-purple socks and boots with shades of purple. She also had square-framed sunglasses on her hair in some shots.
Being older, Yumi is also more impetuous than Ami and rushes headlong into a decision before thinking. However, Yumi has a mature side, too, and sometimes reasons with Ami's childish obsessions.
Yumi loves things like ninjas and anything else rough and tough.
In the pilot, she was depicted as the calm type instead.