Korosensei, The Pervert & Unkillable Assassination target

Korosensei, The Pervert & Unkillable Assassination target

Korosensei was the homeroom teacher of Kunugigaoka Junior High School’s Class 3-E. Korosensei was the assassination target for the student of Class 3-E.

At the beginning of the series, he claimed to be the one who destroyed half of the moon.

He further claimed that he planned to destroy the Earth in March of next year, after teaching the class for one year.


Korosensei is a three meters tall yellow octopus. He has a large swollen face with a large smile and small, beady eyes. His face is like a ‘smiley’.

He has tentacles for arms and legs. He can change the color of his face depending upon his mood.

Korosensei wears a black academic dress and a small academic cap. He uses the black tie with a yellow crescent moon on it; a gift from Aguri.

When Korosensei was a human, he had a slender build with pale skin and black hair. He was the original “Reaper”.


When first introduced, Korosensei appeared jolly and childish. He made ridiculous demands from the students and mocked them for not being able to hit him even once.

However, he was kind and amiable to his students and others in general but he could switch to being serious if deemed necessary.

According to Nagisa’s notes of Koro sensei’s weakness, he was sensitive to other people’s opinions, unintentionally petty, and loved gossip.

We see him trying to sneak into the boy’s and girl’s room to note down their gossip.

Korosensei never liked talking about the past. So, he created lame stories to distract the students whenever they asked him about it.

Korosensei deeply cared about his students and also goes to great lengths for each one of them.

He could connect to every single one of the students and bend backward to help whenever he found any one of his students in trouble.

According to Class 3-E, Korosensei has a total of 40 weaknesses.

One of the weaknesses includes the students of Class 3-E. All the students are well aware of this weakness.

But only three ever dared to exploit it, Nagisa Shiota, Karma Akabane, and Ryoma Terasaka.


Class 3-E

Korosensei cherishes each one of his students and is extremely protective of them. He does not show favoritism for any particular student.

He works hard to be a teacher the students can be proud of. He encourages them and makes sure no one gets left behind.

Korosensei enjoys being a teacher for the students of Class 3-E. His motivation to become a student for this particular class comes from his promise and the last wish of Aguri Yukimura.

So long as I have time… I will use this as a teacher. The students you watch over, I will watch them myself. No matter what, these tentacles will not let them go.

Tadaomi Karasuma

Karasuma always seems exhausted around Korosensei’s cherry manners. He is always exasperated and calls Korosensei an “octopus”.

Meanwhile, Korosensei feels that Karasuma is trying to win over his students and cries over it.

Karasuma, on the other hand, learns to be a better teacher to these students with the help of Korosensei.

In addition to that, he has also asked Korosensei about the welfare of the students.

He also trusts him to keep the children safe and not bring harm to any of them.

Fun Facts about Korosensei

  • Korosensei received his name from the students of Class3-E. His name translates to a “teacher who can’t be killed”.
  • “Korosenai” means “unkillable” and “sensei”.
  • He never actually knew his birth parents or his birth name.
  • He is shown to be very perverted which is also one of his weaknesses. His pervert characteristic is the side effect of the experiment. This made him unable to hide his true feelings.
The tentacles spoke to me, asked what I wanted to be. To be weak I said, to be flawed, vulnerable. To perceive weakness in others is not to exploit but to protect. To be a guide, to be a teacher.

Korosensei is a Mach-20 monster who could have run away. However, he chose to become a teacher for these students who needed him.

He dedicated himself to motivating them to stand proudly in society which considered them the lowest in the rank.

Thanks for reading!!!