|Season||Pretty Cure 5☆Reborn|
|Home Place||Yumekawa (after meeting Kelly)|
|Japanese Voice Actress||Maeda Ai|
|Parents||Minazuki Minako (mother)|
Minazuki Dan (father)
|Siblings||Minazuki Kelly (non-biological younger sister)|
|Alter Ego||Cure Aqua|
Karen has long blue hair, and a single strand in front of her shoulder, and has blue eyes. She is shown wearing her school's uniform. The uniform includes a purple cardigan with a red ribbon and white collar. There is a lilac dress which is worn under the cardigan with button up pleats. There are navy blue knee length socks. There are brown penny loafers for shoes.
Karen is intelligent and can be quite strict at times, but she immediately softened when Kelly told her that they were sisters, and Karen happily hugged her. It is also shown that Karen would do anything to protect her sister, no matter how different they were.
Karen (as Cure Aqua) had appeared in Kelly's dreams ever since she was a child, usually getting defeated.
At the start of PC5R12, Karen (then known as "the mysterious girl") watched Kelly score many goals, but when Kelly saw her, Karen walked off, and left Kelly wondering.
She is next seen walking in a garden at dusk, where the Cures confront her. When Kelly recognises her, she hugs her straight away, which leaves Karen stunned. When Kelly explained everything, Karen smiles and hugs Kelly back, and looked as if she was about to cry.
However, the six girl were soon attacked by a new villain named Bash, but after the Cures transformed, they were almost defeated! Karen then shouted out words of encouragement to Cure Sapphire, and Cure Sapphire then realised how much Karen cared about her. Using her attack, Cure Sapphire managed to defeat the Kowaina that Bash had summoned. Afterwards, Karen and Kelly had a tearful reunion.
- Minazuki Kelly - Her younger twin sister. The two girls appear to care for each other very much, and Karen will do anything to protect Kelly.
Karen's voice actress, Maeda Ai, has participated in only one image song for the character she voices. This song is a duet with Kiuchi Reiko, who voices Minazuki Kelly.
- Beautiful Tomorrow (along with Kiuchi Reiko)