Hamaguchi

Biodata

Personality

Hamaguchi is an outspoken, sociable Class B student who readily joins group activities and banters with his friends. He is particularly patient with Baiye Ying's eccentric behavior, though he openly calls him out when necessary. 7 11 47

He is protective of his classmates and takes Class C's harassment seriously. When Ying dismisses the danger, Hamaguchi stresses that he and Shibata have personally been targeted. 21 He also shows practical judgment, questioning whether Ying's overly elaborate birthday-party plan can stay within budget. 33

Story Role / Major Arcs

Early School Life

• Joins Ying, Kanzaki Ryuji, and Shibata Sou in exploring the club orientation, where he is impressed by the school's extensive club offerings. 7
• Gives Ying an honest negative answer when asked whether he has a “coolness factor.” 11
• Participates in Class B social gatherings and is among the friends who notice Ying only becomes eager to attend once he learns the gathering is at Ichinose's dormitory. 11

Conflict with Class C

• Warns Ying to avoid Class C after its students deliberately knock over Hamaguchi's breakfast and harass Shibata through the soccer club. 21
• Becomes a member of the Byakuya Group alongside Ying, Beppu Ryota, Amikura Mako, and Kobashi Yume during Class B's group-travel response to Class C's harassment. 21
• Helps Ying, Shibata, and Ryota intimidate Class C after its harassment escalates against Class B students. 23
• Acts alongside Ying and Beppu in a theatrical rehearsal intended to support their intimidation campaign against Ishizaki. 24

Class B Special Task Force

• Serves as the Class B Special Task Force's logistics chief, assigned to procure party supplies for Ichinose's surprise birthday celebration. 33
• Reports the operation's available budget and obtains items including balloons, banners, and star lights. 33
• Continues supporting the party preparations when Ichinose unexpectedly begins inviting additional classmates. 33

Uninhabited Island Exam

• Shares Ying's excitement over the upcoming deserted-island trip. 36
• Helps establish Class B's campsite and explains that there are not enough boys' tent spaces for Ying, leaving him to sleep outside. 39
• Calls Ying to Class B's check-in point and later accompanies him on a walk while Ying searches for evidence against the suspected spy Kaneda. 41
• Welcomes Kaneda into Class B and joins the reconnaissance group that verifies Class C's seemingly carefree beach camp. 40
• Remains confident that Ying will return before the island exam's final results are announced. 45

Cruise Ship Return

• Brings Ying the ship's “Tuna Family Bucket,” then watches with resignation as Ying gives an exaggerated gourmet review of every dish. 47
• Joins Beppu and Shibata in card games with Ying; he ultimately exposes Ying's cheating when extra cards fall from Ying's clothes. 49

Relationships

• Baiye Ying / Byakuya — Close friend who frequently worries about Ying's safety, tolerates his eccentricity, and calls him a “brother.” Hamaguchi also arrives to help after Ying intervenes to protect Sakura Airi. 21 30 39
• Shibata Sou — Friend and fellow Class B member; they jointly warn Ying about Class C and work together during Class B's response to the harassment. 21 23
• Beppu Ryota — Friend and Special Task Force teammate; Hamaguchi works with him during Ichinose's birthday preparations and Class B group activities. 22 33
• Ichinose Honami — Class leader whose birthday operation Hamaguchi supports as logistics chief. 33
• Kanzaki Ryuji — Fellow Class B student; Hamaguchi socializes with him and Ying, while Kanzaki later recognizes Ying's contributions to Class B. 7 47
• Kaneda — Initially welcomed by Hamaguchi into Class B's island camp despite Ying's suspicions that Kaneda is a Class C spy. 40

Notable Quotes

“Brothers never lie to brothers.” 21

Trivia

• Hamaguchi is the one who gives Ying the logistics codename Zhe, which Beppu bluntly explains means “buying things.” 33
• He is repeatedly exasperated by Ying's behavior, including Ying's exaggerated food reviews and card-game cheating. 47 49