Separated as a baby from her twin brother, Iori, and lived with her father in Orre for many years. He wasn't the most attentive parent, so she spent most of her time exploring the area, despite it being a boring and dangerous desert. She was eventually given an Eevee to at least have a Pokemon to protect herself with, as she was a mischievous kid.
At the age of 9, she was sent to live with the rest of her family in Kanto, where she originally struggled with not knowing much of the language, or any sign language. As she had difficulties communicating with her brother, she ended up becoming friends with Shigeru instead, but in recent days their friendship is strained as she's become more withdrawn and odd.
Kaori is less interested in the League than Iori and Shigeru, but doesn't want to be left out from their adventures. Instead, she becomes interested in rare Pokemon and rumours of strange, lab-created ones... In LGPE, she's the dedicated Himemi harasser who is also chasing after Mewtwo. She's the only one crazy enough to go after that serial killer psychic lab freak.
Haruna (始菜) is some sort of traveller like her brother, Haruo. Some sorta less-serious ronin. She frequently crossdresses as him, though he doesn’t realize this. Still a crazy lesbian, so finds a way to weasel her way into the royal court to protect all the fine ladies there.
Kaori stalks Iori to find what hick village he moved to, and opens up a café there.