The high school girl whom the nameless salaryman begins a relationship with after the two crash into one another on the stairs of a train station. Feeling guilty for breaking his arm she visits him several times in the hospital allowing the two to get to know each other better. During the day she attends high school and serves as the class representative. She also works parttime as a waitress at one of the Koubeya chain of bakeryrestaurants where she wears the signature bowtie and tartanpattern apron uniforms. She has a younger sister in middleschool who is also well endowed. She prefers to be referred to as Aichan named after her cup size.