Satsu

Biodata

Feature	Information
Name	Kato Satsu (佐津)
Alias(es)	Satsu
Gender	Male
Affiliation	Class D; Tokyo Metropolitan Advanced Nurturing High School
Occupation/Role	Student; manipulator and point trader
First Appearance	Chapter 1

Background

Satsu was originally an ordinary college student who died after saving a girl from a truck accident. He awakened in Kato Satsu's body and spent a month adapting to his transmigration with the help of the original owner's diary. 1

The body he inhabits had a severely injured right wrist before his arrival. He initially could barely clench the hand without pain, and later learns that the injury may leave permanent damage. 1 15

The diary also reveals that Satsu's household was connected to an unidentified powerful figure who supported his mother. A later account describes Satsu attacking his foster mother when she attempted to leave him; after the incident, his body was abandoned, then awoke again less than an hour later with a radically changed temperament. 1 50

He enters Tokyo Metropolitan Advanced Nurturing High School despite not taking its written examination or entrance interview. Sakayanagi Narimori and Sakayanagi Arisu conclude that someone used a proxy test-taker and altered the school system to enroll him. 17

Appearance

Satsu is a tall, conventionally handsome young man whose appearance immediately draws attention from students.

• Jet-black short hair. 1
• Sharp, heroic facial features and a cold, aloof bearing. 1
• Nearly 1.9 meters tall, with a muscular build. 1
• Primarily uses his left hand because of his damaged right wrist. 1 11

Personality

Satsu is openly vain about his appearance and initially approaches school life with self-interest, treating other students as opportunities for points, entertainment, or useful connections. He is comfortable lying, bargaining, blackmailing, and exploiting information gained through mind reading. 1 4 6

Despite this opportunism, he can be generous toward people he considers friends. He spends 80,000 points on dinner for Ayanokoji and Hasebe, supports Ayanokoji when Horikita tries to use him for errands, and ultimately assists with Class D's study-group recruitment. 19 30 48

His confidence becomes unstable when situations exceed his knowledge or control. He grows paranoid about Sakayanagi Arisu's schemes, recognizes that mind reading cannot reveal everything, and is capable of panic under direct physical threat. 19 23 14

Satsu also has a violent, frightening side. After being attacked with a knife, fear gives way to exhilaration as he brutally beats the clerk and nearly kills him before Ichinose intervenes. He later expresses remorse and uncertainty over the violent tendencies connected to his body. 14 15

Abilities & Skills

Mind Reading

Satsu can perceive the thoughts of people he looks at. He discovered the ability roughly half a month after transmigrating and regards it as his greatest advantage. 1

• Reads immediate intentions, hidden motives, and emotional reactions. 1 4 13
• Exposed Matsuyama's relationship with Sae by drawing on Matsuyama's guilty thoughts, turning Kuraku against him. 4
• Anticipated Yamamoto Sae's attempt to frame him for sexual assault and neutralized it by behaving as the apparent victim. 21
• Uses opponents' anticipated next moves to compensate for his lack of formal combat training. 5
• Cannot guarantee complete knowledge: Arisu's planning exposes limits in what he can learn or predict. 23
• Later experiences delayed, non-real-time impressions and headaches while attempting to read Horikita. 44

Improvisation and Manipulation

Satsu rapidly adapts to social conflicts, usually by turning another person's private motives against them.

• Provoked Kuraku into attacking Matsuyama rather than fighting him directly. 4
• Secured Kuraku's remaining points by offering to pursue Matsuyama and Sae's expulsion. 6
• Acquires information, contacts, and cooperation through bargaining, bribes, and strategic favors. 29 36 48
• Uses his wealth to recruit Yamauchi, Sudo, and Ike into the study group. 48

Physical Combat

Satsu has a strong build but states that he has not trained formally. His combat effectiveness relies heavily on reading an opponent's intended attacks. 5

• Blocked and evaded Horikita's strikes by anticipating her follow-up movements. 5
• Disarmed and incapacitated a knife-wielding clerk, though he lost control and inflicted severe injuries afterward. 14
• His injured right hand remains a serious physical limitation. 1 15

Equipment / Items

• School-issued tablet — Taken from the Kuraku–Matsuyama fight and sold for 40,000 points. 4 5
• Second school mobile phone — Purchased for 300,000 points as a “shadow account” with a separate phone number; it cannot independently transfer points. 29
• Black rabbit doll — Gifted by Sakayanagi Arisu; originally contained a hidden micro-camera intended to monitor and implicate him. 21 24
• Diary — Belonged to the original owner of Satsu's body and provides key information about the household and his past. 1 49

Relationships

• Ayanokoji Kiyotaka — Friend and frequent strategic partner. Satsu values Ayanokoji's contact information and later works with him to recruit students for Horikita's study group, though he also briefly helps obstruct that same group. 11 39 48
• Horikita Suzune — Began with mutual hostility after Satsu followed her on their first day. Their relationship develops into tense cooperation around the Class D study group, with each attempting to manipulate the other. 3 44 46
• Haruka Hasebe — Neighbor, friend, and a source of romantic tension. Satsu chooses to accompany her over Inogashira and reassures her after their argument. 6 43
• Sakayanagi Arisu — A calculating rival who repeatedly attempts to engineer Satsu's expulsion. Satsu recognizes her as a serious threat after she turns his countermeasure into a wider trap. 21 23 24
• Ichinose Honami — Business partner. She transfers Satsu one million points under a contract after verifying his financial background; Satsu promises to repay her within a month or drop out. 38 41
• Chabashira Sae — Homeroom teacher who becomes interested in relying on Satsu to help Class D reach Class A. 25 29
• Kikyo Kushida — Friendly on the surface, though both initially approach the friendship with private agendas. She persuades Satsu to participate in the study session. 10 30
• Kato Marumi — His sister, an influential figure connected to the Umbrellas. She investigates his diary and seeks to see him during the school's Uninhabited Island exam. 10 49 50
• Nagumo Miyabi — A target of Satsu's future money-making plans after Nagumo warns him against targeting second-year students for expulsion. 25 32

Story Role / Major Arcs

Arrival and the Kuraku–Matsuyama Incident

After arriving at school, Satsu uses mind reading to expose Matsuyama's deception of Kuraku, triggering their fight and Kuraku's eventual expulsion. He profits by selling the abandoned tablet and extracting Kuraku's remaining points. 4 5 6

Clerk Attack and School Cover-Up

Satsu identifies a clerk's plan to murder him, then retaliates with excessive violence when attacked in an alley. Wolf Spider intervenes through The Web's influence, framing the incident as self-defense compounded by mental illness and securing Satsu's release. 13 14 15

Sakayanagi's Expulsion Scheme

Arisu gives Satsu a rabbit doll containing a hidden camera and manipulates Yamamoto Sae into attempting to frame him. Satsu reads the plan and counters it, but Arisu reveals that she had anticipated both success and failure, leaving him unable to decisively defeat her. 21 23 24

Points, Contracts, and Class D

Satsu accumulates points through wagers, transactions, and manipulation, then purchases a second phone to maintain a shadow identity. He later obtains one million points from Ichinose under a high-risk repayment contract and uses money to recruit reluctant Class D students into Horikita's study group. 29 41 48

Recording Transaction

Seeking control over the recording connected to Yamamoto Sae's framing attempt, Satsu approaches Hashimoto Masayoshi. Sakayanagi raises the price from 300,000 to 500,000 points, which Satsu pays without hesitation. 51 52

Trivia

• Satsu introduces languages as his hobby during Class D's self-introductions. 2
• He wanted to join the Board Game Club because he believed mind reading would make him unbeatable at card games. 7
• He considers reaching Class A alone through 20 million points less troublesome than reforming and uniting Class D. 25