Teacher Yaga

Biodata

Feature	Value
Name	Masamichi Yaga 2
Alias(es)	Teacher Yaga (夜蛾老师); Principal Yaga 9 36
Gender	Male 3
Affiliation	Jujutsu High; Jujutsu Society 3 19
Occupation/Role	Jujutsu sorcerer, teacher, and later principal; leading authority on jujutsu puppet arts 3 34 43
Rank	Grade 1 jujutsu sorcerer 43
Status	Alive ten years after Dazai’s death in the main-story route 34
First Appearance	Finds Dazai hanging from a tree near Jujutsu High 2

Background / History

Early Career and Dazai’s Enrollment

Yaga established himself as the foremost figure in the jujutsu puppet world while still in his twenties. His experience included repeated brushes with death, which later helped him recognize distress beneath Dazai’s composed behavior 43.

On May 11, 2003, Yaga encounters eighteen-year-old Osamu Dazai attempting to hang himself near Jujutsu High. He questions Dazai about his mental health and discovers his nullification ability when physical contact temporarily removes Yaga’s cursed energy and technique. Although he initially refuses admission because enrollment has closed and Dazai is outside the usual entry age, he calls him back rather than leave him alone 2.

During the admission interview, Yaga warns that fewer than half of Jujutsu High’s students survive to graduation. He nevertheless accepts Dazai’s stated desire to find a reason to live, supplies the books needed for his requested third-year placement, and arranges a private dormitory room. He subsequently takes Dazai to breakfast and introduces him to Sōsuke Mizukawa and Nozomu Sakai 3 4.

Protecting His Student

Yaga reports Dazai’s technique as “suppression” rather than nullification and advises him to keep its full capabilities discreet. After Dazai’s disastrous first mission and the attack at Headquarters, Yaga hears his account, grants the students several days off, and offers to teach them if a replacement instructor cannot be found. He also correctly suspects that Dazai deliberately alienated his classmates to keep them away from danger 5 9.

After Mizukawa and Sakai die, Yaga repeatedly tells Dazai that their deaths are not his fault. He reveals that this is his first year teaching and that he has already lost his first-year students. Despite his own grief, he encourages Dazai to keep searching for meaning, suggesting that it may exist beyond Jujutsu Society 13.

Over the following years, Yaga argues with the higher-ups on Dazai’s behalf and repeatedly protects him from being labeled a curse user. He seeks counselors for Dazai, then studies psychology late into the night when professional help proves ineffective 15 25.

Years of Care

Yaga’s care extends to Dazai’s daily needs. He holds his money after repeated losses during river suicide attempts, distributes mission earnings every three days, and intervenes when Dazai attempts to hang himself, drown, or bleed to death. After rescuing him from a river, he stays beside him through a forty-degree fever, emphasizing that Shoko’s Reverse Cursed Technique cannot treat him 14 20 26.

When the higher-ups again demand that Jujutsu High surrender Dazai, Yaga explicitly refuses—even after Dazai suggests exchanging him for better school resources. He asks Dazai to trust him and try harder to keep living 19.

The anniversary side story shows Yaga securing several days off for Dazai, confronting his habit of burying himself in missions around his classmates’ deaths, and inviting him to share his burdens. He feeds him, helps him buy bandages, and sees him safely back to his room 47.

Main-Story Ending and Alternate Route

In the main-story route, Dazai leaves a final letter and some clothing on Yaga’s desk before dying in a fire at the former Jujutsu Society headquarters. Yaga cannot reconcile the sudden loss with his memories of the student he considered his proudest 31 34.

Ten years later, Yaga still visits the site. He believes Dazai had deliberately arranged his death and mourns his inability to give him a reason to remain alive. By this point, Yaga has become principal; Gojo, Geto, and Shoko are among the few students from his teaching years who survived to graduation 34.

In the separate happy-ending route, Yaga confronts the surviving Dazai with his familiar “Iron Fist” and an angry accounting of his misconduct 33.

Extra Stories

During the Book’s screening of Boss Dazai’s life, Yaga compares the fifteen-year-old on-screen with the reserved adult he knew. He is pleased to see Dazai playing and bickering, but footage of his violent behavior leaves him questioning whether he ever truly understood his student 35 39 42 45.

In the New Year special, Yaga receives Dazai’s bloodstained red scarf and keeps it despite the possibility of a trap. After falling asleep, he finds himself outside Port Mafia headquarters, still holding the scarf. He recognizes Chūya Nakahara from Dazai’s descriptions, accidentally addresses him with one of Dazai’s insulting nicknames, and apologizes when Chūya takes offense 50.

Appearance

• Middle-aged: Initially described as fierce-looking and stern 3.
• Sunglasses: Wears them while briefing Dazai and the first-years 15.
• Bearing: Approaches with a steady stride and is seen standing ramrod straight at the school gates 9 19.

Personality

Yaga combines strict discipline with a strong sense of adult responsibility. He is willing to bend admission procedures to help someone in distress, but does not disguise the dangers of sorcerer life. His commitment to Dazai rests less on the student’s exceptional ability than on his conviction that he should not be abandoned 2 3 19.

He is unusually perceptive about Dazai’s performances, recognizing protective motives beneath deliberate hostility and distress beneath theatrical humor. That insight has limits: the screening of Dazai’s past forces him to distinguish caring deeply for his student from fully understanding him 9 42 44 47.

Yaga’s composure develops over his teaching career. His early grief is comparatively easy to read, while the older Yaga is more controlled and dependable. Dazai, Gojo, and Geto can still provoke his temper, earning punches, thrown chalk, and lengthy lectures 13 14 15 19.

Abilities & Skills

Jujutsu Puppet Arts

• Recognized as a leading authority, having achieved that standing in his twenties 3 43.
• Makes Dazai a needle-felted Chūya doll based on his descriptions; no supernatural properties are stated for this gift 50.

Physical Strength and “Iron Fist”

• Uses the recurring “Yaga’s Iron Fist” to discipline troublesome students 9 14 19.
• Can lift the six-foot-tall Dazai with one hand and carry him back to his dormitory 20.
• Retains enough practical strength to restrain and move Dazai while his technique is nullified through contact 14 20.

Observation and Student Support

• Correctly identifies Dazai’s attempt to distance his classmates for their protection 9.
• Uses his familiarity with Dazai and sharp intuition to notice unusual details during the screening 44.
• Studies psychology and seeks professional assistance rather than treating repeated suicidal behavior solely as misconduct 15 25.
• Provides practical care, including wound treatment, fever monitoring, food, and recovery time 20 26 47.

Cursed Energy and Technique

• Possesses cursed energy and a cursed technique, both temporarily nullified when he touches Dazai.
• Their disappearance immediately alerts him to Dazai’s unusual ability; both return after he releases him 2.

Items

• Chūya Nakahara doll — A handmade gift for Dazai. Despite Dazai’s complaints, it remains the only lively-looking object in his otherwise stark dormitory 50.
• Dazai’s final letter and clothing — Left on Yaga’s desk in the main-story ending 31.
• Bloodstained red scarf — Received and retained as a keepsake of his late student in the New Year special 50.

Relationships

• Osamu Dazai — Student, later colleague, and the student Yaga calls his proudest. Dazai identifies Yaga as his deepest bond in the jujutsu world; that attachment motivates him to prevent Geto’s defection and arrange protection for Yaga after his own death 19 21 23 25 27.
• Sōsuke Mizukawa and Nozomu Sakai — Students whose deaths deeply affect Yaga. He explains Dazai’s emotional difficulties to Mizukawa and later tries to relieve Dazai’s survivor’s guilt 11 13 47.
• Satoru Gojo and Suguru Geto — Students who frequently test his patience through classroom mischief and destructive missions. He lectures them about safety and using curtains; both eventually become teachers 19 40.
• Shoko Ieiri — Student and one of the few surviving graduates from Yaga’s teaching years. Yaga recognizes the limits of her healing when caring for Dazai 20 34.
• Jujutsu Society higher-ups — Authorities he repeatedly opposes to protect Dazai. Their pressure does not persuade him to surrender his student 15 19 20.
• Chūya Nakahara — Initially known through Dazai’s complaints and descriptions. Yaga’s first depicted encounter with him begins awkwardly because he knows Dazai’s nicknames rather than Chūya’s name 50.

Notable Quotes

“This isn't a place where you can find meaning in life. No jujutsu sorcerer dies without regrets, and fewer than half survive to graduation.” 3

“Jujutsu High will never abandon a single student, and I will never agree to hand you over.” 19

“Dazai, I want you to be more careful around those higher-ups in Jujutsu Society. I also want you to trust me. I will never give up on you.” 19