Su Weiyu

Biodata

Background / History

Su Weiyu’s uncontrollable ability prevents other people from acknowledging her existence. Neither helping others nor harming them earns a response: even a child she rescued from drowning ignored her. Doctors likewise cannot recognize her need for treatment, forcing her to research illnesses and administer her own first aid 14.

Prolonged isolation once impaired her ability to speak normally. She recovered through practice and developed a habit of talking to herself, rehearsing the introduction she hoped to give someone who could finally see her. She resolved to become that person’s most loyal companion 14.

Su Weiyu took Captain Sparrow’s Compass from the Containment Bureau and followed it for three years, hoping it would lead her to such a person. When it finally pointed toward the Blood Demon House, she researched the site and learned that it had swallowed an S-rank Investigator. Despite recognizing the danger, she entered 14.

Appearance

Su Weiyu is described as a beautiful young woman with delicate brows and highly expressive eyes 10 20.

• Initial clothing: Trousers and blood-soaked clothes; her left arm is bandaged after an encounter with the Blood Demon 10.
• Later clothing: Changes into a white shirt while inside the house 14.
• Distinctive equipment: Carries an odachi taller than herself on her back and keeps a palm-sized compass box behind her waist 10 14.

Personality

Su Weiyu responds to Xia Shou’s attention with intense excitement and affection. Her nervous first greeting contrasts with her otherwise lively manner; even his offer of a hamburger leaves her struggling to speak. She eagerly volunteers to help him and brings an elaborate lunch specifically to win him over 10 21 24 25.

Her loyalty does not depend on fearlessness. Although visibly terrified of the Blood Demon, she lures it away from an immobilized Xia Shou and still tries to give him her Compass after suffering catastrophic injuries. In combat, she can be blunt and decisive, killing an attacker when continued restraint would endanger him 11 12.

Years without ordinary social feedback have left her uncertain about boundaries. She assumes Xia Shou will welcome her moving into his room after consulting online advice, then panics when he reacts with surprise. She is willing to exchange five-star hotels and gourmet meals for a cramped dormitory and cafeteria food if it means staying near him 48.

Abilities & Skills

Transparent Man

Su Weiyu’s ability blocks awareness of her rather than merely making her invisible. Information about her is ignored, while the effects of her actions are accepted as normal. She cannot switch it off 20 21.

• Unnoticed attacks: Victims and immediate witnesses rationalize injuries she inflicts. The Tamer continues attacking Xia Shou after she severs his arms, without recognizing her intervention 11 35.
• Infiltration: She can pass guards, take sealed anomalies, and force open doors without attracting attention 14 35.
• Research concealment: Xia Shou uses her to search Bureau files because an investigation that turns toward her involvement would cause investigators to overlook it. This does not mean the computer records are erased 25.
• Human targets: Even a Level Seven Cleaner could not see her. She explains that a being can retain a human mind despite losing its human bodily shape and still remain unable to perceive her 44.
• Exceptions: Xia Shou can see her. Alice and several nonhuman enemies can also perceive or interact with her 15 39 44 49.
• Delayed observation: People who encounter the consequences afterward can notice something wrong, as the arriving medical team does with the Execution Squad’s severed arms 35.
• No physical immunity: The Blood Demon wounds her, and the sanatorium’s keys deprive her of bodily functions 10 42 47.

Boy Cutter Swordsmanship

Boy Cutter grants its wielder the martial prowess of its former owner, Minamoto no Yorimitsu. Its reproduced techniques become more refined the longer it is carried; Su Weiyu has possessed it long enough to perform strikes ordinary human eyes cannot follow 44.

• Lightning Triple Slash: Delivers three rapid slashes that leave blurred afterimages 39 44.
• Rapid dismemberment: Severs the arms of the Execution Squad before Xia Shou can react 19.
• Area-clearing attacks: Creates a tightly gridded cutting zone and clears a corpse-filled corridor in eight seconds while carrying Xia Shou 46.
• Rule-based limitation: Her blade cannot strike the doctor controlling the Hand and Foot Keys when she operates it with her hands. She bypasses that restriction by holding the hilt in her mouth 44 45.

Investigation and Languages

Su Weiyu combines familiarity with supernatural incidents with practical research skills 27 28 35.

• Recognizes Edward’s equipment and appearance from her research into the Blood Demon House 27.
• Identifies the hospital’s spatial distortion as a Closed Domain 28.
• Reads and translates English records about Idrisu and the sanatorium’s origins for Xia Shou 35 36 37.
• Cannot decipher the unfamiliar scripts in the fortress’s older magical books 35.

First Aid and Combat Coordination

• Self-treatment: Can administer anesthetic and stitch minor wounds, though injuries to her hands make this difficult and serious wounds remain life-threatening 14.
• Controlled restraint: Disarms Liu Guangyao with her sword’s hilt when Xia Shou asks her not to hurt him 28.
• Tactile communication: Helps devise leg-pinch signals for fighting the Ear Doctor while riding on Xia Shou’s back 41.
• Observation: Notices the Yellow-Skinned Patient becoming faster and attempting to open ward doors 30.

Equipment / Weapons / Items

• Boy Cutter: An oversized odachi that reproduces Minamoto no Yorimitsu’s martial skills; her principal weapon 10 44.
• Captain Sparrow’s Compass: A sealed anomaly housed in a palm-sized black box with a golden needle. It points toward what its holder wants, although Su Weiyu experiences years of apparently directionless spinning 10 14.
• Sanatorium keys — temporary possession: Holds and transfers keys during the escape, using the Hand, Foot, and Heart Keys to open the final doors. Xia Shou ultimately gains control of all five 40 42 46 47.

Relationships

• Xia Shou — The person her three-year search finally leads her to. She protects him, assists his research, and seeks greater closeness; he trusts her because of the sacrifice she made in a timeline he remembers 14 15 20 25 48.
• Alice — Xia Shou’s possessing spirit, who can interact with Su Weiyu. Alice prevents her from carrying him away during his immobilization and later obstructs their proposed shared living arrangement, ultimately handing Su Weiyu her bedding and locking her out 12 49.
• Calamity Crystal Dragon Lizard / 678 — Su Weiyu persuades it not to eat Xia Shou by offering double food and a month of reading books aloud. She later cites that obligation as a reason to stay at the Bureau 19 49.
• Wang Long — A fellow survivor of the hospital’s Closed Domain. She assists the group while her ability prevents him from recognizing her interventions 29 37 46.
• Containment Bureau — The source of sealed anomalies she takes unnoticed and the organization that classifies her as Transparent Man. She later conducts research and stays in its dormitory area through her connection with Xia Shou 14 25 35 49.

Story Role / Major Arcs

Blood Demon House

• Meets Xia Shou and guides him to the dead entrants, allowing his shadow to acquire abilities from their bodies 10.
• Kills the Tamer when he attacks the immobilized Xia Shou, then remains beside Xia Shou while his shadow finishes devouring a charred corpse 11.
• Lures the Blood Demon away and suffers catastrophic mutilation. Her final attempt to pass Xia Shou the Compass gives him time to complete Devouring; he subsequently rewinds to attempt a rescue 12 13.
• Finds Xia Shou again through the Compass. Both are caught in the Blood Demon’s lethal spear attack during a later attempt, but another rewind lets Xia Shou warn her to flee before defeating it 15 16 17.
• Protects him from the Execution Squad outside the house and negotiates his release from 678 19.

Bureau Research and Central Hospital

• Brings Xia Shou lunch and searches restricted information about the Death Record Notebook and Root Sea on his behalf 24 25.
• Accompanies him to Central Hospital, where they become trapped in a Closed Domain 25 28.
• Infiltrates the guarded fortress and retrieves the English documents that expose the sanatorium’s origin and Idrisu’s role 35 36 37.
• Is tempted by Idrisu’s promise to cure her transparency condition in exchange for becoming its assistant 38.
• Kills the Eye and Ear Doctors, helps defeat the doctor controlling the Hand and Foot Keys, and cuts down the disguised Heart Doctor and surrounding corpses 39 42 45 46.
• Recovers her bodily functions after Xia Shou imprisons Idrisu; they wait for the domain to collapse back into the original hospital 47.

Dormitory Move

• Secretly prepares a bed in Xia Shou’s room, expecting him to welcome living together 48.
• Accepts the room next door after Alice’s intervention. Xia Shou offers to watch her belongings so they will not be cleared away by cleaners who cannot recognize her ownership 49.

Notable Quotes

“I'm Su Weiyu. It's nice to meet you.”
— The greeting she rehearsed during her isolation 14

“You'll find someone who can see you someday, Su Weiyu... Hang in there.”
— Encouraging herself while trapped in the Blood Demon House 14

“No need to be so polite with me! Just tell me what you need.”
— Offering to help Xia Shou search the Bureau’s records 25