Natsume is a student from class B who acts like a tsundere character toward Sae, masking her strong affection for her by maintaining a generally antagonistic attitude. During her first day at Yamabuki, she faced a lot of troubles and was helped by Sae and touched by her kind nature, developing feelings for her. To her dismay, she was separated into another class and quickly became jealous and envious of Hiro's burgeoning relationship with Sae. Ever since, she has been trying to hide her feelings in Sae's presence by acting nonchalant, initially declaring herself to be her rival. Eventually, though she becomes less confrontational around her and occasionally visits Sae and the others at the apartment, when invited. She is also one of the few people who know of Sae's pen name and is an admirer of her books.