Takashima Zakuro

Yuki's schoolmate from a neighbouring class, Zakuro, is the protagonist of the "Looking-glass Insects" chapter. She has a tendency to get lost in her thoughts and frequently spaces out. Due to her timid and soft-spoken nature,

Spoiler

she is often a target of tasteless pranks and bullying

. She considers her classmate Kimika to be her only friend, though their relationship appears to be occasionally ambiguous.