Masamichi Yaga (
Masamichi is a tall man with short black hair that is shaved at the side of his head, a mustache goatee combination, and wears sunglasses.
Masamichi wears a zipped up long sleeved black jacket, black pants, and black shoes.
A year before the series began, Masamichi wore an open black jacket over a zipped up high collar white shirt.
As a teacher, Masamichi wore the same clothes but didn't wear his sunglasses, and had a shaved head that had two line that wrapped around his head.
Masamichi Yaga is a stern and serious individual who prides himself as an educator. He dislikes those with faulty motivations due to his past with Suguru Geto. He also appears to like cute things as many of his cursed corpse dolls resemble stuffed animals and plushies.
At some point in the past, Masamichi became the principal of the Tokyo college. Masamichi had also created Panda, and trained him. Masamichi also explained to Panda that he had an older brother and sister.
Years ago, Masamichi punished Gojo for not putting up a screen when Gojo along with Geto and Shoko check up on Utahime and Mei Mei. Later Masamichi meets with Gojo and Geto, where he gives them a mission from Tengen. Masamichi informs the two about the importance of the mission, and that there will be two group that they will have to look out for. Later, Masamichi is contacted by Gojo about their circumstance which he tells them to follow Riko's request since this is Tengen's orders.
A year later, Masamichi informs Gojo about how Geto had killed an entire village and is currently on the run. Masamichi also informs Gojo that Geto had also most likely has killed his own parents after going on the run. Later, Masamichi meets with Gojo after Gojo has met with Geto.
Cursed Child Arc
Masamichi meets with Gojo, and talks about how they have to locate Geto. When Geto suddenly shows up at the college for Yuta, Masamichi along with other Sorcerers go to confront Geto. After Geto makes his proclamation about an all-out war and leave, Masamichi attends a meeting where they discuss their course of action.
Masamichi meets with Gojo and Yuji for an interview to see if Yuji will attend the school. When Gojo and Yuji arrive at the meeting place, Masamichi says that they are late. When Yuji introduces himself, Masamichi asks him why he is here. Yuji says that he is here to help people because it was the last request from his grandfather, Masamichi doesn't like his response and says that he is disqualified. Masamichi then has more of his corpse dolls attack Yuji and explains what it is and that it will continue to attack until Yuji gives him an answer he likes.
As Yuji is continued to be attacked by the doll and trying to give a reason, Masamichi explains what a Sorcerer does and how most of them die. When Yuji says that he will never regret how he lives, Masamichi accepts this answer and welcomes Yuji to the school.
Cursed Training Arc
Days later Masamichi goes to meet with Gojo, but notices that Gojo is late.
The next day, Masamichi is to attend a meeting with the Kyoto college principal, Yoshinobu, but is told by Gojo the wrong time of the meeting.
Kyoto Goodwill Event Arc
On the day of the Kyoto Goodwill Event, Masamichi is with Yoshinobu when Gojo reveals that Sukuna's host, Yuji, is still alive. Masamichi then explains the rules of the event along with Gojo, while put Gojo into a hold.
When the event starts, Masamichi is with the other faculty watching the event through monitors. When intruders invade the site, Masamichi heads over to go find Tengen. After the intruders have been dealt with, Masamichi attends a meeting with the other faculty and informed of the casualties and what was stolen from the invasion. After they all discussed about how they should keep what was stolen a secret from the higher-ups, Masamichi suggest that the Kyoto Goodwill Event be over.
After it is decided that the event will continue, Masamichi is surprised that the next day event is baseball. Masamichi then watches the game along with Yoshinobu. During the game, Masamichi talks with Yoshinobu about Yuji.
Shibuya Incident Arc
On October 31, Masamichi has Shoko set a tent near Shibuya, to help out wounded Sorcerers. As Shoko tells him that she doesn't need him to be around, but Masamichi explains how they need to protect Shoko since she is the only one that can use Reverse Technique. When Megumi shocks up, Masamichi is surprised by this and wonders about how he thought he saw either Yuji or Sukuna.
Abilities and Powers
Great Cursed Energy: As a Sorcerer and the principal of the Tokyo Metropolitan Curse Technical College he has a Cursed Energy grid in which he makes use of controlling puppets to attack enemies.
- Masamichi ranked 40th place in the manga's 1st Character Popularity Poll with 233 votes.
- He taught Geto, Gojo and Shoko.
- He owns a lot of glasses.
- His catchphrase is "Goddamn!".
- Although he likes cute things, it's not his intention to make his cursed corpses cute.