Yui has light skin and big friendly maroon eyes. Her dark blue hair is medium-length and worn in braided twin-tails held by the ear. Her spiked bangs are evenly spread out with a split at the middle of her forehead. She wears glasses. When not in the school uniform, her formal attire is composed of a light blue shirt over a chiffon turtleneck with stripes and light brown skirt, paired with a yellow hat. During summer, she wears a mint blouse and light yellow shorts, and for winter she wears a flutter-sleeved mint top over a white shirt, yellow shorts, gold boots with black tights, and a white hat.
Friendly and very helpful to the extent that she can, Yui is described by Towa as "the sun for Pretty Cure", in that her kindness and hope is what reminds them on what is truly important. Even if she can't become a Cure herself, she knows she can still make a difference.
Meeting Haruka and Becoming the First Target
When Haruka arrives at Noble Academy, Yui appears and shows her around. Haruka goes into the forest and Yui follows her, only for Close, one of the generals of Dys Dark, to lock her dream of being an author away and create a Zetsuborg. She is soon freed after Haruka, who transformed into Cure Flora, purified it.
Yui's voice actress, Yoshimura Haruka, has participated in an image song for the character she voices. This duet is sung with Shimamura Yu, who voices Haruno Haruka.
- I'll be Fine Tomorrow Right?! (Along with Shimamura Yu)
- Yui shares the same name with Nao's youngest sister, Midorikawa Yui.
- She is the first character in this series who had her dream taken more than twice.
- She is also the first character to fight back from within the Cage of Despair, thereby allowing the Cures to defeat the Zetsuborg created from her dream.