Lulu Shiizaki (椎崎るる) attends St. Mihailov Academy. She embodies the archetype of the academically gifted classmate whose profound difficulty with social interaction marks her as an outsider. Peers perceive her as aloof and bookish, leading to isolation and a lack of true friendships.

This strained social dynamic arises partly from challenging family circumstances. Following her father's departure, Lulu's mother neglects household duties, consumed by increasingly desperate and unconventional attempts to reclaim him. This forces Lulu to shoulder all domestic responsibilities alone, without parental support. The resulting stress and instability fuel her easily provoked and defensive reactions.

Intense pride further defines Lulu's personality, making her deeply reluctant to discuss her family problems or seek help. This emotional barrier cements her isolation, preventing her from confiding in others about her home life struggles.

A pivotal moment occurs when Lulu accidentally discovers that her classmate Ekaterina Kurae's innocent, doll-like persona is a carefully constructed facade. However, Lulu's attempt to expose this deception fails; her existing reputation as a social misfit leads classmates to dismiss her claims, deepening her isolation within the class.

Physically, Lulu possesses black hair and striking red eyes. Her character design typically features braids, glasses, and pigtails, reinforcing her studious image.