Naoya Matsumoto’s monster manga has already published its 129th and final chapter.
Kaiju No. 8 is a manga series by Naoya Matsumoto that began publication in July 2020. Published by Shueisha on their Shonen Jump+ platform, the manga is released in English by Viz Media. It became one of the biggest shonen names of this era after the release of its action-packed anime adaptation in 2024.
However, that doesn’t mean the manga series is far behind in popularity. With great battles against formidable kaijus, cool futuristic weapons, and a protagonist with a compelling backstory, Matsumoto created something very special. But after the final chapter, fans have some questions.
Warning: Spoilers ahead!
What’s Kaiju No. 8 even about?
Kaiju No. 8 (Kaijū Hachigō) is an action manga series which takes place in a world where massive monsters known as kaijus run rampant. Japan, which is the main hub of kaiju activity, has a dedicated team of soldiers known as the Japanese Anti-Kaiju Defense Force (JAKDF) to fight these monsters.
The protagonist for this manga is Kafka Hibino, is a 32-year-old man who works as a Cleaner. His job is to clean up kaiju remains after the JAKDF is done taking them down. But early on in the series, we learn that he used to be childhood friends with JAKDF’s Third Division’s Captain Mina Ashiro.
Both Kafka and Ashiro lost their homes and families to kaiju attacks when they were children. They made a promise to grow up and become JAKDF officers and fight the monsters together. But as time passed, Mina was selected to become a Defense Force member due to her amazing aptitude at handling massive weapons, while Kafka was left behind.
But things change for Kafka at the age of 32 when he meets his junior Reno Ichikawa. The 18-year old influenced Kafka to take the JAKDF exam one last time with him. Surprisingly, they both pass, but things change almost immediately for Kafka.
After surviving a kaiju attack somehow, Kafka and Ichikawa end up in the hospital. While lying there, the protagonist is visited by a small flying Kaiju. Before he could panic, the monster enters Kafka’s body through his mouth, giving him the ability to turn into a disaster class monster known as a daikaiju.
As he’s the 8th disaster class Kaiju to be identified, the Defense Force names him Kaiju No. 8, hence the title of the manga. With his future at the JAKDF on the line, Kafka tries to hide his truth from everyone but Ichikawa. This gives birth to a hilarious, yet action-packed story that shows a common man’s journey to fulfill his promise of fighting beside his friend, and save humanity during its most dire moment.
Is Kaiju No. 8 good?
In a word, the answer would be yes. The manga has all the elements of becoming a fan-favourite series. From the get-go, it has great action. The monster designs are clean and intimidating, which gives fans a clear idea of how disastrous the disaster class Kaijus actually are.
Some JAKDF members also have ‘Numbered Weapons’, which are equipment made from the body parts of slain daikaijus. Matsumoto did a tremendous job of designing these weapons to perfectly fit the characters that wield them.
This gives birth to a manga that’s so entertaining and exciting that you won’t be able to stop once you start reading.
However, the series is not without its flaws. Other than Kafka and maybe Kikoru Shinomiya, no other character shows a lot of development due to the manga being only 129 chapters long.
Although we see characters such as Ichikawa, Furuhashi and others becoming stronger, they don’t get a lot of screentime compared to the protagonist. Even Mina, who’s Kafka’s main influence in life, often falls flat when it comes to development.
In my opinion, Kikoru Shinomiya is the most compellingly-written character in the story and surpasses even the protagonist with her growth and maturity. At first, she came off as haughty and proud, due to her excellent combat skills and high potential. But after a devastating tragedy, the youngster was faced with the realities of life. With the help of friends who supported her unconditionally and superiors who doted on her, she was finally able to face her own past and became a fighter her parents would be proud of.
She grew so strong in fact, that Kikoru Shinomiya became the first person to wield two Numbered Weapons, surpassing even her mentor Gen Narumi.
It seems that with most of the focus on the monsters and action, the story and characters of the manga are often forgotten. Although the pacing never falters, the lack of depth makes the manga lose its re-reading value.
The manga’s final chapter was published on 17 July, 2025, and without giving out too many spoilers, I’d just say I’m disappointed.
The ending was very run-of-the-mill and felt like it was cut short. I would’ve liked to see a few more chapters to tie up loose plot ends that will keep bothering me forever. The most important one of those being the origin of Kaijus, which was never explicitly explained in the manga. The final two chapters felt rushed and sloppily patched to hide plot holes.
Overall, it makes the series a bit disappointing, but not enough to completely abandon it altogether.
Should you read Kaiju No. 8?
Once again, the answer to this question will be yes. It’s easy to recommend this manga because of its simple plot and exciting action. The pacing of the story is fast and non-complicated, which makes it a perfect fit for newbie manga readers just getting into the genre.
Much like Demon Slayer, Kaiju No. 8 is easy to read and understand, with a perfect amount of fast-paced action to match. However, due to the rushed ending and lack of character depth and development, veteran readers might not enjoy the series.
Most importantly, there’s not much re-reading value in Kaiju No. 8. This means people will likely only read it once.
However, I’m still holding out hope that a sequel manga will come out eventually, with how things were left in the end. Thankfully, the anime is doing a great job of bringing the best of the manga to life on screen.
