Miharu Mikuni

First appearing when she returned a misplaced acceptance letter, this high school classmate shares a complicated bond with Keita. Though she maintains a distance to avoid his sisters, her frequent blushing and comfort during his hugs reveal a deep, hidden attraction. Despite her shy demeanor and struggles with social inexperience, she remains a central figure in his life, often caught in the middle of the twins' chaotic antics while harboring intense, private fantasies about him.