Assassination Classroom has become a seemingly overnight sensation in the U.S. with a second season of the English-dubbed anime highly anticipated. This anime follows the day-to-day lives of E-Class rejects at a prestigious middle school where classism is alive and well. The other students look down on them and the Principal does everything in his power to keep E-Class oppressed.
However, what the rest of the school doesn't know about Class-E is that they are being trained to become assassins by a failed military experiment that has threatened to destroy the Earth if no one in the class can assassinate him by the end of the school year. Even with this motivation, Koro-Sensei is quite the target. Not only is he insanely fast and powerful, he genuinely cares for the students and wants them to succeed in life. The students have loved his teachings in assassination, school, and life lessons, making the task at hand all the more difficult.
10 Always Believe in Yourself
The students in Class 3-E all have incredibly poor self-images due to their status in school. Some of the students even fell from good graces which makes them feel worse than the kids who have just always been labeled as bad eggs. They are under the impression that no one cares about what happens to them so why should they?
When Koro-Sensei arrives, he learns about each of his students and what makes each one of them special and what they are each capable of. He constantly creates lessons and study materials that highlight each of the students individually and he encourages them to always be who they are and that they are all capable of great things. Koro-Sensei was the first... person that believed in these students, and in turn, it allowed them to start believing in themselves.
9 Sometimes You Need to Fail in Order to Succeed
Lessons learned rarely come without failure, and the students of Class E are certainly no strangers to this concept. Koro-Sensei is very skilled at knowing which buttons to push for his students to have a meaningful reaction to failure. Some students constantly try and always seem to come up short, whereas other students are overly cocky and don't feel the need to take things seriously.
When the first type of student fails, Koro-Sensei is there to support and encourage them for the next time. He also typically provides specific study materials to help them improve in the areas that they struggled in previously. However, with the second type of student, specifically Karma, Koro-Sensei knew the only thing he would respond to was teasing, so he messed with him about his poor test results until Karma snapped, but in a way that made him try harder to succeed.
8 Be Prepared For Anything
Koro-Sensei has been known to be overly prepared for most occasions, most notably when going on a trip, he goes to the effort of putting together a guidebook for his class. On a two-day trip to a nearby city, Koro-Sensei prepared 26 guidebooks for his class with 1,334 pages each. While this did serve comedic purposes, the guidebook actually ended up saving the day on a few occasions.
The guidebook had an entry for every eventuality Koro-Sensei could possibly fathom, which ended up helping Nagisa, Karma and the others find their classmates that had been kidnapped by high school students. Once they found the hideout, Nagisa reads through everything in the guidebook that helped them track down the ne'er-do-wells, which turned out to be a lot.
7 Never Underestimate Your Opponent
While Koro-Sensei is the first to believe in his students, he also understands the realities of life and makes sure that his students always properly assess an opponent and understand the risks before rushing in overconfidently. Most notably, his students tend to underestimate him the most as he is their primary target.
Toward the end of the first season, the entire class pulls off a coordinated attack on Koro-Sensei that causes him to unveil his ace in the hole which keeps him safe from the onslaught. Though, had it not been for his fail-safe maneuver, Koro-Sensei would have been bested by his students as they applied all of the knowledge they had learned about their opponent into one final effort.
6 It's Important to Know Your Strengths
Because of their wacky new teacher, each student has a better understanding of what they bring to the table. While Mr. Karasuma is also great at positively critiquing his students, he is only around for a subject or two whereas Koro-Sensei is the primary instructor responsible for most of their education.
The students now know what their best traits are when it comes to school as well as when it comes to assassination. Koro-Sensei continues to nurture their strengths while also helping them overcome certain weaknesses.
5 Strive to Improve Your Weaknesses
Every student in Class E has some weaknesses they need to work on, though some are more willing than others. Koro-Sensei does an excellent job of identifying each student's weaknesses and then creating lesson plans to help improve their weaker areas.
These lessons are typically in the form of schoolwork, but the lessons extend into real life many times as well. Working on improving and overcoming weaknesses strengthens the individual overall. The fewer weaknesses one has the less likely they can be exploited.
4 Teamwork Makes the Dream Work
While the government has promised money to the individual who successfully assassinates Koro-Sensei, the students know that teamwork is an invaluable resource, even if it means splitting the money. Many students have formed small groups when attempting to off their teacher.
The closest that the students ever came to defeating their teacher in season one was at the end where the entire class worked together and coordinated an air-tight attack. Unfortunately for the students, Koro-Sensei narrowly avoided death due to an unknown special ability that he used at a last-ditch defense.
3 Don't Concern Yourself With What Others Think, Especially Those Who Don't Know You
Once Koro-Sensei had boosted the confidence of his students, he reminded them that they must not let the words or actions of others distract from their progress, especially not their vindictive Principal. In addition to their awful Principal, most students on campus treat E Class students like third-rate humans.
Though after a few lessons with Koro-Sensei, the students of E Class were not only able to ignore the other students but were even able to counter or embarrass them on a couple of occasions. Without the constant weight of judgment on their minds, the E Class kids have become academic leaders.
2 It's Important to Play By the Rules (& Exploit Them When You Can)
While Koro-Sensei is a stickler for the rules on many occasions, he is no stranger to bending them in his favor, and he teaches his students to do the same. Most notably was during the exhibition baseball game between the school's baseball team and E Class. Koro-Sensei made sure that his team played by the rules to avoid any additional bias.
Later in the game, E Class turned the tables by cheating in the same way that the baseball team had been cheating earlier. However, since the umpire never called out the team, E Class was essentially grandfathered, which resulted in their victory much to the surprise and disgust of the rest of the school.
1 Rivalry Breeds Friendship
Despite being pitted against each other for a bounty of 10 billion yen (~$91.6M), the 26 students end up developing close bonds as they are constantly finding different ways to achieve the same goal. Many of them have become decent friends and even team up based on their strengths for assassination attempts on Koro-Sensei.
Koro-Sensei has been an invaluable educator and mentor to E Class and because of him, they will all likely go on to do better things. While this lesson may not have been taught directly by Koro-Sensei, it is his presence that created the bounty thus giving the students their common goal to work towards together.