|Season||Miracle Project Pretty Cure: System REJECT|
|Home Place||Luminous Town|
|Alter Ego||Cure Joker|
Yuu Arimoto (優 有本 Yuu Arimoto?) is sarcastic, rebellious, and easy-going 16 year old girl. Her parents are divorced and her mother has full custody, but she spends her time with her dad. Yuu lives a very privileged life, but she doesn't care for that lifestyle. Yuu doesn't like rules and can't stand it when people can't make mistakes. She and Asuka bicker a lot due to their differences. She often plays harmless jokes on other people, and she refers to herself as "The Ace of Fools". As Cure Joker, she introduces herself as "The ace of fools, Cure Joker!". Her theme colors are black and white.
Yuu has short, messy silver hair and magenta eyes. She is albino, a trait she shares with her father. Yuu has rather fair skin, and she usually wears punk clothing. When she is at home she dresses more casually in over-sized sweatshirts and comfy jeans. She has a large tattoo of a tiger on her back.
As Cure Joker, her eyes become brighter and her hair spikes a bit.
Yuu is sarcastic, loud, rebellious, and carefree. She prefers to let things happen as they will and usually doesn't get involved in other peoples affairs. She doesn't get close to many people, but those who she does get close to are very important to her, and she will do just about anything for them.
"The Ace of Fools! Cure Joker!!"
"Orokamono no ēsu!! Kyua Jōkā!!"
Cure Joker (キュアジョーカー Kyua Jōkā?) is Yuu's Pretty Cure alter ego.
優 (Yuu) - It means "superiority".
- Yuu is the second Pretty Cure to have divorced parents, after Miki Aono.
- Yuu is the third Pretty Cure to have black as a theme color, after Cure Black and Dark Precure.
- Yuu is the sixth Pretty Cure to have white as a theme color, after Cure White, Cure Egret, Cure Ange, Cure Rhythm, and Cure Echo.
- Yuu is the first Pretty Cure to have a tattoo. (she has a yakuza-inspired tiger covering her back)
- Yuu is the first Pretty Cure to have white hair. (Not including Setsuna as Eas)
- Yuu is the second Pretty Cure to play guitar.