Assassination Classroom Review: I Came for the Comedy and Left With a Broken Heart

I Thought This Was Just Going to Be a Fun Anime

When I started watching Assassination Classroom, I knew absolutely nothing about the story.

I had not seen any spoilers. I did not know what would eventually happen to Koro-sensei, and I definitely was not prepared for how emotional the final episodes would become.

At first, I thought this was simply going to be a fun school comedy.

Then the last few episodes arrived and broke my heart into pieces.

Seriously, damn this anime.

The first episode immediately caught my attention. Koro-sensei suddenly entered the classroom, and almost every student immediately started shooting at him.

I was sitting there wondering what kind of school I had just entered.

Then the anime explained that this strange yellow creature had destroyed most of the moon and was supposedly planning to destroy Earth. Because he could move at Mach 20 and was far too powerful for the government to defeat, the students of Class 3-E were given a mission: assassinate their teacher before graduation.

The student who killed him would also receive a massive cash reward.

It sounded ridiculous.

A government assassination mission carried out by middle-school students against a smiling yellow octopus teacher? How could that possibly become emotional?

I had no idea what I was getting myself into.

The Worst Class Somehow Received the Best Teacher

Class 3-E was treated like the failure class of Kunugigaoka Junior High School.

The students were isolated in an old classroom on the mountain and used as a warning to everyone else. They were supposed to feel ashamed, inferior, and afraid of falling behind.

Then Koro-sensei appeared.

He was supposedly a monster planning to destroy the planet, but he became a better teacher than almost every normal human teacher in the series.

He helped the students with their studies, understood their individual weaknesses, protected them, encouraged them, and taught them how to face the world with confidence.

Yes, he trained them to become assassins.

But he also trained them to become better people.

The students gradually became stronger throughout the series. They learned how to plan, fight, cooperate, observe people, control their emotions, and believe in themselves.

At first, I genuinely thought Koro-sensei was simply turning a group of children into top-level assassins.

I was both wrong and correct.

They did become incredible assassins, but assassination was never the most important lesson he was teaching them. The real purpose was helping them discover their own abilities and choose the lives they wanted to live.

Nagisa and Karma Became Two of My Favorite Students

Nagisa Shiota and Karma Akabane were two of the most memorable characters in the entire series.

Nagisa initially appeared quiet, harmless, and physically weak. However, whenever he entered assassination mode, he became terrifying.

Koro-sensei recognized Nagisa’s natural ability to observe people, hide his presence, and strike at exactly the right moment. He helped transform Nagisa into a skilled assassin, but Nagisa eventually chose to become a teacher.

That ending felt perfect.

Nagisa did not simply copy Koro-sensei. He carried Koro-sensei’s lessons into his own life and began helping troubled students in the same way his teacher once helped Class 3-E.

Karma, on the other hand, was confident, intelligent, violent, and always entertaining. He could be incredibly lazy, but when something truly interested him, he became almost unstoppable.

By the end of the story, Karma was working toward a career in government and politics.

It was satisfying to see both of them grow into adults without losing the personalities that made them special.

I Honestly Thought Koro-sensei Was an Alien

One of the biggest surprises was discovering the truth about Koro-sensei.

I genuinely thought he was some strange alien monster.

Instead, he was originally a human and one of the most dangerous assassins in the world, known as the Reaper.

After being betrayed and captured, scientists experimented on him using antimatter technology. Those experiments transformed him into the creature we knew as Koro-sensei.

The truth completely changed how I saw him.

Before becoming a teacher, he was a cold and terrifying killer. He trusted very few people and treated human lives like part of his work.

Then he met Aguri Yukimura.

Aguri Yukimura Brought Out the Kindness Inside Him

Aguri’s death was one of the most tragic parts of the story.

She was engaged to the scientist responsible for the experiments, but he treated her terribly. Despite being surrounded by cruel people and dangerous experiments, Aguri remained kind.

She continued speaking with the Reaper while he was imprisoned and slowly formed a genuine connection with him.

I like to think of Aguri and Koro-sensei as a couple. The anime may not spend much time officially defining their relationship, but their bond clearly changed both of their lives.

When Koro-sensei escaped, one of the traps created to kill him struck Aguri instead.

Her death changed him forever.

Aguri was the person who brought out the kindness buried inside the world’s greatest assassin. She showed him another way to live, and Koro-sensei decided to fulfill her dying wish by becoming the teacher of Class 3-E.

However, I do not think Aguri magically created a kind person out of someone completely heartless.

I believe almost everyone has a kind side somewhere inside them. Sometimes, it simply takes the right person to bring that side to the surface.

For Koro-sensei, that person was Aguri.

Kaede Kayano’s Secret Completely Surprised Me

Kaede Kayano’s true identity was another revelation I never expected.

She was actually Akari Yukimura, Aguri’s younger sister.

After seeing the aftermath of Aguri’s death, Kayano believed Koro-sensei had killed her. She secretly joined Class 3-E, changed her identity, and carried artificial tentacles while waiting for an opportunity to take revenge.

She did not know the complete truth.

However, I cannot completely blame her for what she believed. Her sister had died, she was grieving, and everything she saw made Koro-sensei appear responsible.

Grief does not always allow people to investigate every detail calmly. Sometimes, people hold onto the explanation that matches the pain they are feeling.

Her confrontation with Koro-sensei was emotional because it was not simply a fight. It was the collision between Koro-sensei’s guilt and Kayano’s grief.

Itona Was So Annoying at First

When Itona Horibe was first introduced, I wanted someone to punch him.

He kept appearing with the crazy idea that he was Koro-sensei’s brother because they both had tentacles. He was aggressive, unstable, and completely obsessed with defeating him.

Thankfully, he eventually became a good character.

After escaping the influence of the people who had been controlling him, Itona slowly became part of Class 3-E. His development showed how the class could accept even someone who originally entered their lives as an enemy.

He was still strange, but he became their strange classmate.

Irina and Karasuma Were My Favorite Couple

My favorite couple in the series was easily Irina Jelavić and Tadaomi Karasuma.

Irina was completely ridiculous.

She was supposed to be one of the world’s best professional assassins, but whenever Karasuma was around, she often behaved like an immature child trying desperately to get his attention.

Karasuma constantly attempted to remain serious and professional because of his government position. Meanwhile, Irina flirted with him, argued with him, and created chaos around him.

Their personalities were completely different, and that was exactly why their interactions were so funny.

Seeing that they eventually got married made me extremely happy.

Among all the tragedy in the ending, at least the anime allowed this relationship to have a satisfying conclusion.

The Moon, the Mouse, and Koro-sensei’s Final Deadline

The explanation behind the moon’s destruction also surprised me.

The moon was damaged because a small mouse used in the antimatter experiments eventually exploded. The same type of experiment had been performed on Koro-sensei, which made the government believe he would eventually suffer the same fate and destroy Earth.

Koro-sensei was essentially considered a walking time bomb.

Class 3-E refused to accept that conclusion without investigating it themselves.

These students literally launched themselves into space, infiltrated a space station, and obtained information that suggested Koro-sensei’s chance of exploding was extremely low.

That entire section was ridiculous, exciting, and completely in character for the series.

After everything they discovered, I began to believe there might actually be a way to save him.

That hope made the ending even more painful.

The Final Battle Made Me Believe He Might Survive

Near the end, the government surrounded the mountain with advanced technology and trapped Koro-sensei inside the area around the old classroom.

Class 3-E responded by launching their own guerrilla operation.

They used the assassination skills Koro-sensei had taught them to break through the government forces and reach him.

Watching the students apply every lesson from their teacher was incredible. They were no longer the weak and frightened students who entered Class 3-E at the beginning.

They had become capable, confident, and united.

Then Koro-sensei had to fight his former student—the second Reaper who had stolen his identity and transformed himself into a monster.

There were so many intense and epic moments that I genuinely began believing the story might give us a happy ending.

Surely, after everything the class had accomplished, the government would understand.

Surely, Koro-sensei would survive.

I was wrong.

The government remained determined to kill him.

Those 🍩.

The Final Attendance Check Broke Me

The moment that truly broke me was Koro-sensei’s final attendance check.

The students pinned him down, preparing to complete the assassination mission they had been given from the beginning.

But before Nagisa could strike, Koro-sensei called every student’s name one final time.

He checked the attendance of the entire class.

Even in his final moments, he was still their teacher.

He wanted to make sure every student was present.

He wanted to say goodbye to each of them.

Then Nagisa stabbed him.

Koro-sensei smiled and slowly disappeared into glowing particles until there was nothing left.

That scene hurt far more than I expected.

The entire premise of the anime had always been about the students killing Koro-sensei, but by the time they finally succeeded, it was the last thing any of them wanted.

They had completed their mission.

They had also lost one of the most important people in their lives.

Of Course He Left Them an Enormous Life Guide

As though the final attendance check had not already caused enough pain, the students later discovered the massive books Koro-sensei had written for them.

They were personal guides explaining how each student could navigate life after graduation.

Come on.

The anime had already killed him. Did it really need to hurt us again?

Those books perfectly represented Koro-sensei.

He knew he might not be there to guide his students forever, so he prepared something that could continue helping them after he was gone.

He did not only teach them how to pass exams or complete assassinations.

He prepared them for life.

The Old Classroom Never Felt Empty

The final episode, where the former students gathered again to clean their old classroom, was also deeply emotional.

They had grown up and followed different paths, but that classroom continued connecting them.

It reminded me of something real.

Most people eventually meet at least one teacher they can never forget.

Sometimes, that teacher enters our life almost by coincidence. At first, we may not realize how important they will become. Then years later, we understand that they helped shape the person we became.

Koro-sensei was that teacher for Class 3-E.

The classroom was old, isolated, and considered a place for failures. However, for those students, it became one of the most important places in the world.

The Opening and Ending Songs Hurt Differently Now

After finishing the series, even hearing the second season’s opening and ending songs makes me emotional.

Those songs bring back memories of the classroom, the assassination attempts, the trips, the ridiculous comedy, and the time the students spent together.

Scenes that once felt funny now carry a strange sadness because I know how little time they actually had.

That is one of the most painful parts of finishing a story like this.

The memories were happy.

Remembering them is what hurts.

Maybe some of our most painful memories are painful precisely because they were once our happiest ones.

Final Thoughts

Assassination Classroom started as a comedy about a group of students trying to murder a yellow squid-like monster.

It ended as one of the most heartbreaking stories I have watched.

The anime showed that education is not simply about memorizing information or receiving good grades. A great teacher recognizes the potential inside every student, including the ones everyone else has already labelled failures.

Koro-sensei taught Class 3-E how to fight, study, communicate, fail, recover, and move forward.

More importantly, he taught them how to live.

The series also reminded me that we should appreciate the small moments we have with people. Time can feel endless while we are living through it, but eventually we look back and realize how quickly everything disappeared.

Class 3-E did not have much time with Koro-sensei.

But they had fun.

They grew.

They became better people.

And they never forgot him.

I do not think I will ever forget that strange yellow squid alien monster either.

My final rating is 9.5/10.

Do not ask me why it is not a perfect 10. Nothing is perfect.

Even Koro-sensei made mistakes. His greatest failure may have been not recognizing the hatred growing inside the student who betrayed him, stole his identity, and eventually returned as one of his greatest enemies.

But that is part of the point.

Every teacher makes mistakes.

Every student makes mistakes.

Every person makes mistakes.

Nobody is perfect, and perhaps that is exactly why the imperfect time Koro-sensei spent with Class 3-E became so meaningful.

Time was too short.

But they had fun.

And when Koro-sensei called attendance for the final time, every one of his students was there and apparently kuro sensei greatest weakness is us...