Yamauchi

Biodata

Feature	Value
Name	Yamauchi Haruki (山内)
Alias(es)	“Grandpa Yamauchi” (self-styled) 5
Gender	Male
Affiliation	Class D, Advanced Nurturing High School
Occupation/Role	Student; Takeda Eito’s reluctant informant and errand-runner
First Appearance	Chapter 2

Background / History

Yamauchi enters Class D at the start of the school year and immediately tries to befriend Takeda Eito. Eito initially pretends to have entered the wrong classroom rather than be associated with him, privately judging Yamauchi’s social reputation to be disastrous. 2

During the class self-introductions, Yamauchi boasts that he reached the national table-tennis tournament in elementary school and was a high-school-league baseball ace in middle school. Eito undermines him by claiming to have injured him in that league; while Yamauchi loudly objects, the class recognizes the inconsistency in his own story and laughs at him. 4

He becomes fixated on Kushida Kikyo after exchanging contact information with her, mistaking her universally friendly behavior for romantic interest. He seeks Eito’s advice, confesses to Wang Meiyu by mistake instead of Kikyo, and is rejected. 3 5 6

After losing a swimming bet to Eito and Sudo, Yamauchi is prohibited from speaking to Kikyo. Desperate to resume contact with her, he accepts Eito’s offer to lift the restriction in exchange for gathering intelligence on Class C. Eito convinces him that he is a government secret agent by crushing a stone one-handed, securing Yamauchi’s fearful obedience. 10 12

Yamauchi’s early attempt to spy on Ryuen Kakeru fails when he is discovered and beaten. Eito subsequently keeps him in Class D to monitor Ike Kanji and Sudo Ken instead. 13

During the island examination, Yamauchi brings the apparently abandoned Ibuki Mio back to Class D. After Eito identifies Ibuki as a Class C infiltrator, he repeatedly sends Yamauchi to harass her and disrupt her efforts to gather information. 37 39

Later, Yamauchi finds Ryuen unconscious after Joker buries him near the sea and helps call for rescue. Ryuen is nevertheless disqualified from the island examination. 50

Appearance

Yamauchi is portrayed as a conspicuous, unpolished student whose mannerisms often draw negative attention.

• Described as having a “sleazy face” and swaggering gait. 12
• Becomes pale and hollow-looking after being unable to approach Kikyo following the swimming bet. 12
• Often reacts physically and dramatically, including kneeling, kowtowing, saluting, or rolling away when intimidated by Eito. 7 12 18 19

Personality

Yamauchi is boastful, lecherous, and notably oblivious to how others perceive him. He inflates his accomplishments, assumes ordinary friendliness means romantic interest, and repeatedly pursues Kikyo despite rejection and social consequences. 3 4 5 6

He is easily frightened and highly susceptible to manipulation. Eito repeatedly exploits his desire for approval, access to girls, and promises of future wealth; Yamauchi responds by treating Eito as a superior and following orders with little scrutiny. 12 18 19

Despite betraying Eito once, Yamauchi becomes intensely loyal once brought under his influence. Eito considers his particular talent to be serving as a lackey, while also recognizing that his obnoxious behavior can be useful for unsettling or distracting targets. 7 18 39

Abilities & Skills

Information Gathering

Yamauchi serves as Eito’s informal source of gossip and observation.

• Was assigned to listen for developments in Class C and report them to Eito. 12
• Collected mostly private gossip about Class C’s girls rather than useful strategic intelligence. 13
• Was caught and beaten while attempting to investigate Ryuen. 13
• Later monitored Ike and Sudo within Class D. 13

Harassment and Distraction

His intrusive behavior makes him useful as a deliberate nuisance.

• Was ordered to bother Ibuki in order to impede her infiltration of Class D. 37 39
• Continues pestering Ibuki despite her cold responses. 38 39
• Eito describes him as a “weapon for disgusting people” when used strategically. 39

Self-Proclaimed Athletic Background

• Claims to have competed in national table tennis and played baseball as an ace pitcher, though his account is discredited by the class. 4
• Finishes well over forty seconds in the swimming race against Koenji, Sudo, Eito, and Ayanokoji. 10

Equipment / Items

• Camera in the girls’ changing room — Installs a camera during the swimming-class period out of jealousy toward Eito’s closeness with Kikyo. 9

Relationships

• Takeda Eito — Classmate who initially rejects Yamauchi’s friendship, then turns him into an informant and subordinate through intimidation and incentives. Yamauchi calls him “Boss” and expresses near-religious admiration for his strength. 2 12 18 19
• Kushida Kikyo — Yamauchi’s primary romantic obsession. He misreads her friendliness as attraction, attempts to confess, and remains preoccupied with speaking to her after losing the swimming bet. 3 5 6 12
• Ike Kanji — Crude friend and fellow member of the so-called “Idiot Trio.” The two argue over Kikyo, fight each other, and compete in childish activities. 5 39 42
• Sudo Ken — Fellow member of the “Idiot Trio.” Yamauchi helps Eito lure Sudo to a secluded alley and is later insulted by Sudo for acting as Eito’s dog. 7 18 19
• Ibuki Mio — Yamauchi brings her to Class D after finding her injured. He later repeatedly harasses her on Eito’s instructions after she is exposed as a Class C mole. 37 39
• Ryuen Kakeru — Yamauchi’s attempt to investigate Ryuen ends with him being beaten; later, he helps summon aid after finding Ryuen unconscious on the island. 13 50

Story Role / Major Arcs

Class D Introduction

• Attempts to recruit Eito into his social circle, only to be publicly avoided. 2
• Provokes Chabashira Sae by asking for her underwear and is summoned to the faculty office. 2 3
• Embarrasses himself through exaggerated self-introduction claims and Eito’s counter-joke. 4

Kushida Pursuit and Eito’s Recruitment

• Mistakes Kushida’s friendliness for affection and seeks advice on confessing. 3 5
• Confesses to Wang Meiyu by mistake and is rejected. 6
• Loses the swimming bet, then bargains with Eito for permission to speak with Kikyo. 10 12
• Becomes Eito’s informant after accepting the fabricated story that Eito is a secret agent. 12

Sudo Subjugation

• Helps Eito lure Sudo into an alley for their confrontation. 18
• Openly praises Eito while Sudo is being subdued, then flees when Eito threatens to make him train with Sudo. 18 19
• Joins Eito’s after-school tutoring sessions alongside Sudo and Ike. 19 20

Island Examination

• Brings Ibuki to Class D, unaware that she is infiltrating for Class C. 37
• Is used to keep Ibuki distracted and uncomfortable while Eito monitors her. 37 39
• Assists in Ryuen’s rescue after Joker’s attack, though Ryuen is disqualified from the examination. 50

Trivia

• Yamauchi calls himself “Grandpa Yamauchi” during his fight with Ike. 5
• He believes hiding beneath a classroom podium until police are called qualifies as evidence of his intelligence. 42
• He is introduced to Ibuki as Class D’s “genius” by Eito, who uses the claim sarcastically to frustrate her. 42