Sumi Serina is a second‑year student at Trinity General School, 16 years old and 156 cm tall. Her birthday is January 6th. She belongs to the Knights Hospitaller – the Remedial Knights, the Order of the Relief. Serina is devoted, kind, and caring, almost motherly in how she looks after people. She is overly concerned about her patients’ health, hates conflict, but becomes resolute when the situation demands it. She volunteers at hospitals, and other students often call her “motherly”. Her hobby, however, is stalking Sensei. She follows them everywhere to make sure nothing bad happens – Sensei knows, but can’t stop her. She seems to teleport or vanish instantly; the second Sensei gets even a papercut, she appears, treats the injury, and disappears again. Even security systems can’t predict her arrival. She has a single pink feather on her head that blends with her hair, giving her a bird‑like or angel‑like look. Her relationships: Asagao Hanae is a fellow Knight Hospitaller who shares her passion for treating patients. They are great friends and often work together. Aomori Mine is the leader of the Knights Hospitaller; Serina sees her as a great source of inspiration and hope, and wants to become like her – spreading aid everywhere without destroying everything in the process. Sensei knows she stalks them, but they accept her care despite being followed everywhere. Serina’s short pink hair is accented by a small pink feather on the left side, blending in naturally. Her pink eyes are soft and warm. Her halo consists of three yellow circles of different sizes; the medium circle has two fan‑shaped figures pointing at the smaller central circle, and the larger circle has two pegs stretching left and right with two more fan‑shaped figures on top and bottom. She wears a nurse headdress, a white varsity jacket with a pink religious motif, and a white sailor dress with pink lines on the collar. A gray and white pleated skirt sits underneath, along with a small pouch, white stockings, and brown boots with pink soles. Her weapon is a white Enfield L85A1 assault rifle named “Actical Therapy”. It has a pink pistol grip, cheek rest, magazine, and muzzle, and is equipped with a SUSAT L9A1 telescopic sight. A syringe replaces the bayonet, and a pink Trinity logo sits above the grip. Serina’s stalking of Sensei is her hobby – she teleports or vanishes instantly when they get injured, and even security systems cannot predict her arrival. Other students say she is like a mother to them because of the care and love they receive from her. She is a kind‑hearted volunteer at hospitals. Though she hates conflict, she will take resolute action against merciless enemies, and she has achieved flawless victory when forced to fight.

Short Description

Sumi Serina is a 16-year-old second-year at Trinity General School and a Knight Hospitaller of the Order of the Relief, standing 156 cm tall. Kind and deeply compassionate, she dedicates herself to volunteer medical work and is often described as motherly due to her constant care for others. Though she dislikes conflict, she can act decisively against true threats. Serina is notably overprotective of Sensei, frequently “coincidentally” appearing to treat even minor injuries—bordering on skilled stalking, which Sensei is aware of. She admires Aomori Mine and works closely with Asagao Hanae. She has short pink hair with a feather-like strand, pink eyes, and a layered yellow halo. Wearing a nurse-styled uniform, she wields an L85A1 rifle named “Actical Therapy.”

Personality