Masamichi Yaga

Biodata

Background

Yaga is a veteran jujutsu sorcerer with decades of field experience. Before Sherlock’s enrollment, he taught Satoru Gojo, Suguru Geto, and Shoko Ieiri, all of whom continue to treat him as their teacher after leaving his classroom. Geto’s defection leaves him especially concerned about the psychological damage dangerous assignments can inflict on students 16 17 113 221.

As Tokyo Jujutsu High’s principal, Yaga handles recruitment, assignments, examinations, relations with Jujutsu Headquarters, and the consequences of his former students’ misconduct. He recognizes the higher-ups’ efforts to undermine Gojo and deliberately declines to help them rein him in when Gojo’s proposals remain lawful and compliant with regulations 7 12 97 109.

Education

Appearance

• Large, burly build: His imposing figure is compared to an iron tower 50 109.
• Gangster-like appearance: His stern face repeatedly reminds others of a yakuza boss; anger makes the resemblance more pronounced 2 3 109.
• Sunglasses: Wears sunglasses, including during emotional moments and confrontations with his students 10 109 156.

Personality

Yaga is stern, reasonable, and protective. His first interaction with Sherlock is an apology for Gojo’s recruitment methods, and he explicitly tells Sherlock to retreat rather than risk his life during his assessment mission. When that mission goes wrong, Yaga worries not only about his survival but also about his mental state 3 12 16.

His anger frequently takes the form of physical “guidance,” scolding, and written punishments. Nevertheless, he sometimes allows misconduct to pass when he sees genuine emotional value in it: he tolerates Gojo and Sherlock’s early antics because Gojo has not laughed so freely since Geto’s defection. He also wonders whether teacher and student are helping to save one another 3 8 35.

Beneath his intimidating appearance, Yaga enjoys soft, creative hobbies, including needle-felting dolls and reading fanfiction. He is not above using questionable methods himself, such as recruiting students with photographs of Gojo cross-dressing or teasing Gakuganji about Tokyo’s new undergraduate status 109 178.

He values the refuge the school community finds at Sherlock’s House. At a banquet there, he is both grateful that such a haven exists and guilty that he could not provide it for his students himself 197.

Abilities & Skills

Artificial Cursed Corpse Creation

Yaga creates fully independent artificial cursed corpses, including Panda. This achievement is specifically associated with his identification as a Semi-Special Grade sorcerer 162 213.

• Autonomous creations: Panda is a fully autonomous cursed corpse rather than an ordinary panda 213.
• Physical modification: Yaga reinforces Panda’s bones so that he can withstand the recoil of the Thunderfire Prayer Beads mounted on his gauntlets 216.
• Training dolls: Makes the doll used to train the stability of Sherlock’s cursed-energy output 109.
• Group training: Supplies approximately one hundred dolls for Gojo to use in Sherlock’s reaction training 38.

“Righteous Guidance”

Yaga’s fists are repeatedly described as instruments of “righteous guidance.” He uses them to discipline Gojo, Sherlock, Geto, and eventually Shoko 3 122.

• Authority over former students: Both Gojo and Geto instinctively submit to his discipline despite their Special Grade strength 5 120.
• Rapid punishment: Uses a barrage called Guidance-Guidance Gatling to suppress the fighting at Gojo’s birthday party 142 143.
• Limits of the portrayal: The narration humorously says his fists can break through Limitless and rival Special Grade cursed tools; it does not explain a separate cursed technique behind these descriptions 90 164.

Teaching and Assessment

Yaga teaches both jujutsu-related material and ordinary academic subjects, while maintaining disciplinary and examination standards 14 91 97 189.

• Classroom influence: Sherlock recalls Yaga’s serious lectures during his first mission, including conclusions that contradict the textbook 14.
• Academic oversight: Supervises Sherlock’s final examinations and explains that students may choose a foreign language other than English 97.
• Corrective instruction: Conducts a week of Ideological and Moral Education lessons for Gojo, Shoko, and Sherlock after the first Goodwill Event scandal 91.
• Written discipline: Assigns Gojo a five-thousand-word reflection for injuring Sherlock and Sherlock a ten-thousand-word reflection for attacking his teacher 35.

Strategic Judgment

Yaga recognizes both the military value of cursed techniques and the political dangers surrounding their users 18 127.

• Technique evaluation: Immediately recognizes Sherlock’s teleportation as strategically valuable after experiencing it while conscious 18.
• Political foresight: Warns Gojo that the higher-ups could try to turn Sherlock into a weapon against him once they discover his ability to bypass Limitless 18.
• Counterintelligence support: Deliberately stays in an outside hospital to cooperate with Gojo’s investigation into a suspected spy among the higher-ups 127.
• Threat assessment: Warns Gakuganji that Sherlock’s increased destructive power could ruin Kyoto Jujutsu High 176.

Dollmaking and Design

Yaga’s fashion-design education accompanies a longstanding interest in making dolls 109 136.

• Takes online doll commissions through an alternate account 109.
• Sells custom dolls depicting the Gojo/Sherlock pairing; Sherlock discovers that Yaga made dolls he had purchased for Shoko 109.
• Browses fanwork sites for what he calls “inspiration” 109.

Relationships

• Satoru Gojo — Former student and current teacher under Yaga’s administration. Yaga disciplines him but also shields his lawful reforms from the higher-ups. Gojo’s commitment to protecting Sherlock helps their strained relationship begin to heal; later, Gojo seeks Yaga’s advice after struggling with his own student 7 18 68.
• Sherlock — Student of Yaga’s former student and a recurring source of administrative trouble. Yaga safeguards his early missions, supports sending him abroad for protection, and later studies in his graduate-exam preparation course 16 136 162.
• Suguru Geto — Former student whose defection continues to weigh on Yaga. Geto remains instinctively afraid of his teacher’s fists and eventually calls him in tears to complain about Sherlock’s harassment 16 120 122.
• Shoko Ieiri — Former student and school medical practitioner. She reports misconduct to him, but also participates in schemes against him, including drugging him for the Hokkaido “forced vacation” 5 17 35.
• Panda — Yaga’s autonomous cursed-corpse creation, regarded as his “child.” Yaga provides him with a room at home, fears Sherlock will corrupt him, and modifies his body to accommodate new equipment 140 141 216.
• Yoshinobu Gakuganji — Fellow principal and a figure described as both mentor and friend. Their relationship is repeatedly strained by Tokyo’s conduct at the Goodwill Events, though Yaga remains concerned for his health 77 178 189.
• Kinji Hakari and Kirara Hoshi — Recruits brought in through Yaga’s unconventional use of Gojo’s cross-dressing photographs. He later oversees their participation in the Goodwill Event and reminds them that ordinary academic examinations still await them 109 189.
• Naobito Zenin — Receives Yaga’s warning letter after Sherlock announces his intention to accompany Gojo to the Zenin Clan over Maki’s obstructed enrollment 203.

Story Role / Major Arcs

Sherlock’s Admission and First Mission

Yaga first appears in his office making a doll when the police call about Gojo’s arrest. He retrieves Gojo, apologizes to Sherlock, and explains the invitation to Jujutsu High. After Sherlock accepts Gojo’s offer, Yaga immediately anticipates the trouble their partnership will cause 2 3.

Before Sherlock’s Grade 2 assessment, Yaga emphasizes that survival takes priority over completing the mission. He also informs Gojo of the assignment beforehand—a precaution that allows Gojo to reach Sherlock when faulty intelligence exposes him to a Grade 1 cursed spirit 12 16.

Hokkaido “Forced Vacation”

Shoko drugs Yaga, Gojo carries him, and Sherlock transports the group to Hokkaido without his knowledge. Once he understands what happened, Yaga gives only a superficial reprimand and enjoys the rare break himself 16 17.

The trip ends after Gojo, Shoko, and Sherlock consume an entire month of his salary at a king crab restaurant. Back at school, Yaga confronts Gojo about Sherlock’s strategic importance and the higher-ups’ likely interest in exploiting him 18.

The First Goodwill Event

Yaga helps organize the event with Gakuganji, then finds himself answering for Sherlock’s attacks on Kyoto’s students. When Sherlock apparently summons Gojo and the competition deteriorates further, Yaga concedes on Tokyo’s behalf 77 84 87.

Leaked footage turns criticism toward Yaga’s own teaching. He arranges a discreet return to Tokyo and leaves an apology letter, unaware that Gojo replaces it with an insulting drawing. Gakuganji’s subsequent complaint leads Yaga to impose a week of moral-education lessons on Gojo, Shoko, and Sherlock 90 91.

Protecting Sherlock from the Higher-Ups

Geto’s Return to His Teacher

During the Okinawa investigation, Sherlock summons Geto directly before Yaga. Yaga confronts his former student about becoming a Special Grade curse user and leading the Time Vessel Association, reducing Geto to a frightened request to apologize 120.

When Geto later calls about Sherlock’s repeated bedside harassment, Yaga finds Sherlock reenacting his reactions for Gojo and Shoko. He punishes all three, briefly interrupting the harassment before Gojo joins Sherlock in renewing it 122.

Gojo’s Birthday Party

Gojo steals Panda from Yaga’s home while Yaga is away handling a complaint. After discovering Panda amid the party’s brawl, Yaga rushes to Sherlock’s House and forces the participants to kneel for an explanation 140 141 142.

He ends the renewed fighting with Guidance-Guidance Gatling and imposes restrictions on Gojo’s access to Panda, Shoko’s contact with the Fushiguro siblings, and Sherlock’s use of transportation and summoning on the children. He and Gojo nevertheless lift the broader prohibition on the children interacting with Sherlock 142 143.

Sherlock’s Return and the Academy Upgrade

After returning from China, Sherlock pressures Yaga to approve his employment at Jujutsu High. Yaga refuses and directs the matter to Gojo, remaining unharmed despite online reports describing him as Sherlock’s hostage 154 155 156.

Later, while Yaga is taking his postgraduate entrance examination, Gojo and Sherlock fight on campus and turn the playing field into a lake. Yaga races back, punishes them, and strikes Gojo again when he asks to keep it 167.

Sherlock subsequently uses the official seal and documents from Yaga’s unlocked office to upgrade the school without consulting him. Yaga learns that he is now principal of Tokyo Independent Jujutsu Academy, an undergraduate institution with new Medical and Physical Education colleges 172.

The Later Goodwill Event

Yaga warns Gakuganji against allowing an exhibition match involving Sherlock, but proceeds after learning that influential clans and the higher-ups want to assess Sherlock’s strength. During the student competition, he pointedly defends Tokyo’s unconventional equipment as its “undergraduate approach to combat” 176 178.

The resulting destruction eventually hospitalizes Yaga alongside Gakuganji. After seven days, Yaga insists that Sherlock stay away from their discharge to avoid provoking another medical emergency, then collects Tokyo’s students and announces Hakari and Kirara’s victory 184 189.

Panda’s Equipment and New Students

After learning that Sherlock has transferred the Thunderfire Prayer Beads to Panda, Yaga reinforces Panda’s bones to handle their recoil 216.

He also continues assigning missions and managing Gojo’s curiosity. When he gives Sherlock an unusually specific mission, Yaga immediately takes Gojo and the first-years elsewhere rather than allowing the teacher-student pair to become involved together 218.

Equipment & Personal Items

• Blood-pressure medication and Quick-Acting Heart-Saving Pills — Regularly carried in response to the stress caused by Gojo and Sherlock. Yaga gives medication to Gojo when he seeks advice and later shares it with Gakuganji 68 113 176 178.
• Dollmaking materials and creations — Used for his personal hobby, online commissions, and cursed-energy training aids 2 38 109.

Notable Quotes

“I am very sorry for causing you trouble.” 3

“Satoru, you need to understand that once the higher-ups learn about this, they'll spare no effort to win Sherlock over and turn him into a weapon against you.” 18

“Rest assured, Principal Gakuganji. We at Tokyo Jujutsu High have always had a conscience. What you're seeing is merely our school's undergraduate approach to combat, keeping pace with the times. You're only a technical college, so it's understandable that you wouldn't comprehend it.” 178

Trivia

• Healing immediately after receiving Yaga’s disciplinary punches makes him regard the act as a provocation and hit harder—a lesson Sherlock learns firsthand 91.
• His driver’s license is revoked after his rush back to the school during Gojo and Sherlock’s fight. He later briefly forgets this while taking Kyoto’s school bus to collect Tokyo’s students 167 189.
• Despite repeatedly fearing Sherlock’s influence, Yaga eventually stays silent about his planned confrontation with the Zenin Clan because he is afraid Sherlock might destroy the school—or Yaga’s own home—if provoked 203.