In an attempt to infiltrate Pretty Cure, attend Yuunagi Junior High as exchange students. She and her sister eventually end up befriending both Saki and Mai and later assists Pretty Cure in taking down the Dark Fall.
Kaoru is a teenager with indigo purple eyes and long cerulean blue hair, styled back with a prominent forehead.
She usually wears the Yuunagi Middle School uniform. As a member of Dark Fall, she wears a grey robe with a blue jewel necklace and boots. As Cure Windy, she wears a flowing long-sleeved light blue garment with indigo purple tights, blue ear studs and white boots.
During her time with Dark Fall, her eyes had no light reflection, but after gaining the power of the wind, she has light reflections in her eyes, symbolizing an awake mind and her emotional growth.
Like Michiru, Kaoru is curious about the Land of Greenery due to being sheltered from the outside world. She initially serves as a Dark Fall spy, but is conflicted about their purpose after becoming friends with the Cures. Kaoru acts cold and dismissive, but is also calmer and more rational than Michiru, though she may come across as too frank to others.
- Kiryuu Michiru: Kaoru and Michuru share a close knit sisterly bond. Along with her sister she begged Akudaikan to stop so that she can change her own fate but ended up being seemly destroyed/imprisoned, though fortunately they were later freed. Kaoru usually lets Michiru speaks for her and once admitted to Hyuuga Minori that she is amazed by Michiru's ability to communicate with others.
- Hyuuga Saki and Mishou Mai: Although Kiryuu Kaoru and her sister are initially sent to destroy Hyuuga Saki and Mishou Mai by getting close to them she ends up making friends with them instead. When Goyan used the Fairy Carafe to resurrect the old villains again she comes back with the help of Moop, Foop and Princess Filia and helps Saki and Mai defeat them again.
- Hyuuga Minori: Confused by her behavior at first, Kauro began taking a liking to Minori and became close to her. Before going into Dark Fall, Kaoru insisted that Saki should stay behind as Minori would be sad if something bad happens to her, only for Saki to remark that she will also be sad if the same should happen to her.
Kiri (霧?) - means "fog" or "mist".
yuu (生?) - means "pure".
Kaoru (薫?) - means "scent", which represents the scented winds, due to her powers.
Michiru and Kaoru were created by Akudaikan to stop the Fountain of Sky from being resurrected. While there, they sometimes expressed feelings of loneliness, taking comfort in each other. One day, they saw two fairies in trouble and saved them, though did not give it much thought afterwards.
Later on, Michiru and Kaoru were forced to fight their friends, Hyuuga Saki and Mishou Mai. Instead of fighting, because of their newly gained friendship with the two, Michiru and Kaoru sacrificed themselves to rescue Saki and Mai from their leader, Akudaikan. As a result of this, all memories of them in the Land of Greenery disappeared.
After the Dark Fall manages to steal the Fairy Carafe and resurrect all of the defeated denizens, Michiru and Kaoru are revived and join forces with Saki and Mai against the Dark Fall.
The two sisters decide to confront Akudaikan but they followed by the Cures. During the last battle, the Sky Tree grants Moop, Foop, Flappy and Choppy new power, enabling Saki and Mai to become Cure Bloom and Cure Egret while Michiru and Kaoru get the powers of the Moon and Wind respectively, to become Cure Bright and Cure Windy. They defeated Goyan together with Spiral Heart Splash Star.
Power of the WindDuring the last battle, Kaoru is given the power of the Wind to become Cure Windy, as Mishou Mai reverts to Cure Egret. In this form, Kaoru performs Spiral Heart Splash Star with Cure Bloom, Cure Egret, and her sister, Kiryuu Michiru, who acquires the power of the moon and became Cure Bright.
- Michiru and Kaoru are the first villains who become heroic characters and live on Earth.
- While Kiriya was the first villain who was willing to be reformed, he didn't survive through to the end of his series, but was reborn in a new human body with no memories of his past life.
- She is the first character to be portrayed by two voice actresses, Yuka Imai and Akemi Okamura.
- Kaoru's first voice actress, Yuka Imai, stepped down from the role when she became pregnant and was frequently bedridden due to morning sickness (source). She also voices Tarte's mother from Fresh Pretty Cure!, Minamino Misora from Suite Pretty Cure! as well both Ai and Princess Marie Ange from Doki Doki! Pretty Cure. Her second voice actress, Akemi Okamura, not only voices Foop, but also Hosshiwa from Happiness Charge Pretty Cure!.
- She shares her first name with Kaoru from Fresh Pretty Cure!.