Misaki Yamamoto
A first year in high school, Misaki is the Zaitsus' next door neighbor, as well as their childhood friend. She has a very open relationship with her neighbors, and even comes into Mamoru's room through his window. She somehow knows submission techniques, and can perform them instinctively in her sleep. Spoiler Though she claimed she had no interest in relationships at the moment, she developed a thing for Yuuji Arihara when he shoved a lollipop in her mouth (showing an example to his friend, Yoshihiko Bessho).