Yuigahama Yui

Biodata

Feature	Value
Name	Yuigahama Yui (由比滨结衣)
Alias(es)	Tuanzi; “Yuze-kun” / “Little Ze” for Bai Yuze 17 19
Gender	Female
Affiliation	Bai Yuze and Yukinoshita Yukino’s survival group in the Sunshine Residence Rules Horror 17 19
Status	Alive
First Appearance	Chapter 15 (heard screaming); formally introduces herself in Chapter 17 15 17

Background / History

In Bai Yuze’s earlier loops within Sunshine Residence, Yui arrives during the second week of the second loop. Bai, who has no conscious memory of previous attempts, joins her to clear the second floor; they are killed when the entity on the third-floor stairwell splits in two. In the following loop, Yukinoshita Yukino joins them, but the trio again dies while attempting the third floor. 24

In the current loop, Yui is brought into the residence under the nickname “Tuanzi.” She reunites with Yukino and meets Bai, immediately acting as the group’s social bridge despite the pair’s hostile exchanges. 17

A fake version of Yui attempts to lure Bai and Yukino out of their room. The real Yui later arrives after being deceived by the same impostor and reports the moving corpse in Room 102. 18

Appearance

Yui’s hair is styled in a bun-like shape, which leads Bai Yuze to call her “Tuanzi.” During the residence trial, she suffers unexplained burns and later receives corrosive injuries to her hands. 17 19 42

• Often described through her bright smile and energetic mannerisms. 17
• Uses a phone, including its flashlight, while exploring dark areas. 40
• Temporarily wraps herself and Yukino in a bedsheet to protect them from leaking water. 40 41

Personality

Yui initially presents herself as cheerful, somewhat airheaded, and eager to keep peace between others. She gives Bai affectionate nicknames, uses “Yahallo!” as a greeting, and repeatedly intervenes when Bai and Yukino argue. 17 19

Beneath that behavior, Yui fears becoming a burden and prefers to let Bai and Yukino handle difficult decisions. Bai directly confronts her reliance on others, forcing her to acknowledge that she has been avoiding initiative out of fear of holding the group back. 37

When separated from Bai in the basement, Yui drops her “Tuanzi” facade. Encouraged by Yukino, she becomes focused and confident, analyzes the poem-like clues, proposes practical solutions, and insists on escaping so she can help Bai. 39 40

Abilities & Skills

Intuition and clue recognition

Yui can identify meaningful details without immediately being able to explain why.

• Recognizes Yang Peng in a group photograph by intuition. 42
• Retains and produces Bai’s clue note after falling into the basement. 39
• Helps interpret the poem’s references to a candy-loving monster and surviving in darkness. 39

Cooperation and improvisation

Yui contributes practical ideas during exploration and adapts to dangerous conditions.

• Suggests posing as cleaning staff to enter an anomaly’s room. 28
• Carries Yukino through the adhesive stairwell when Yukino lacks the stamina to do so. 38
• Designs a bedsheet-based method for avoiding corrosive ceiling leaks and rehearses coordination with Yukino. 40
• Reports everything she learned in the basement to Bai without omitting details. 42

Emotional support

Yui frequently stabilizes group dynamics despite her own fear.

• Mediates Bai and Yukino’s arguments and stresses that they must cooperate to escape. 17
• Seeks Yukino for comfort after being tricked by the fake Yui. 18
• Remains concerned for both Bai and Yukino even when the situation forces her to choose escape over staying behind. 42

Equipment / Items

• Phone — used as a flashlight in the basement; later handed to Bai along with its lock-screen password. 40 43
• Clock — temporarily entrusted to Yui by Bai after he freezes time in Room 104; she is told to smash it if the next day arrives before his return. 43
• Scalpel — lends it to Bai when he decides to use self-harm to recover loop memories. 24

Relationships

• Bai Yuze — Survival ally who calls her “Tuanzi.” Yui calls him “Yuze-kun” and “Little Ze,” relies on his analysis, and becomes determined to help him rather than wait to be rescued. 17 19 39
• Yukinoshita Yukino — Close friend and teammate. Yui seeks Yukino’s comfort, carries her through the stairwell, and works with her to navigate the basement and true first floor. 18 38 40
• Male Corpse — Initially feared as a threat, but later understood to have protected Yui as its roommate and ally; its scalpel deterred another monster from entering their room. 49
• Yamauchi Haruki — Makes Yui uncomfortable through his leering behavior and attempts to pursue her. 20
• Yang Peng — A previous player whose notes guide Yui’s group. Yui instinctively recognizes him in an old group photograph. 40 42

Story Role / Major Arcs

Sunshine Residence arrival

Yui joins Bai and Yukino’s alliance after her scream draws Yukino out of Room 101. She introduces Bai to Yukino and helps keep their hostility from undermining the group. 15 17

Second-floor exploration

Yui participates in investigating the residence’s rules and anomalies. Though she initially takes a passive role in planning, she contributes the cleaning-staff strategy and later assists in obtaining the second-floor Zhenxie Guiqi. 28 32 33

Growth confrontation

After Yamauchi flees, Bai challenges Yui’s habit of acting as a harmless mascot rather than voicing her own ideas. Her fear of burdening the group becomes explicit, beginning her shift toward more active participation. 37

Basement separation

Yui and Yukino fall through the anomalous stairwell into a basement area. There, Yui regains her confidence, collaborates with Yukino to interpret clues, and helps devise their escape route. 39 40

When a one-person exit appears, Yui escapes at Yukino’s insistence and returns to Room 102. Despite attracting monsters by running through the halls at night, she reaches Bai and urgently relays the basement’s conditions so he can rescue Yukino. 42

False-rule revelation

Bai explains that the basement note attributed to Yang Peng cannot be treated as absolute rules. Yui realizes that the evidence she and Yukino trusted may have been arranged to manipulate them, but still insists on helping save Yukino. 43

Trivia

• Bai’s “Tuanzi” nickname comes from Yui’s bun-like hairstyle. 19
• Yui’s initial “airheaded” presentation is described as an act; when pressed into action, she displays confidence and analytical ability. 39
• The Male Corpse’s protection allowed Yui to avoid the residence’s emotional effects even when she did not close her eyes overnight. 49