Izumi Yuuka is the president of the gardening club and its sole member besides Kenichi. She is a young teenage girl of average height, with long black hair styled into two back braids and some fringe in the front. Typically dressed in her school uniform or swimsuit at school, Izumi always wears glasses.
A shy girl, she harbors a crush on Kenichi, though he remains unaware of it. Her attempts to ask him out are consistently interrupted. Friendly and kind-hearted, Izumi is polite and particularly shy, especially around Kenichi. Despite hearing rumors about him, after getting to know him, she realized they were untrue and accepted him for who he is. Her feelings gradually develop into love, although Kenichi does not reciprocate them. Nevertheless, he cares deeply for her as a friend, showing kindness and concern for her well-being, such as when he was furious over Daimonji using her as a hostage and was determined to rescue her.
In Ryozanpaku, Izumi feels jealous of Miu because of her own love for Kenichi, leading her to join Niijima's plan. She also envies Miu's figure, wondering how someone so young could be so well-endowed compared to herself. Despite this, she and Miu are good friends, caring for each other equally. Although aware of Kenichi's feelings and relationship with Miu, Izumi respects his choices while still trying to win his affection.
