Sumi Ikuina  

, 生稲 雛美

The character you're referring to symbolizes the Animal Kingdom. Despite being gentle-hearted, she doesn't mind Ikkou and occasionally tries to defend him verbally but fails, allowing him to be mistreated. Her compassion extends particularly towards animals, which seems to be her spiritual strength. In a second season episode, she is pursued by dogs and receives their excessive affection as a result of her inadequate training. Additionally, Yuuko often teases her about her large breasts.