Explaining Naoya Matsumoto, Author of "Kaiju No. 8" | Previous Works, Who Creates the Spin-Offs and Novels?

The manga "Kaiju No. 8," which is currently serialized on "Shonen Jump+," began airing as a TV anime in April 2024.

Kafka Hibino, who had given up his dream of joining the Defense Force that exterminates kaiju and was working as a cleaner, decides to aim for the Defense Force once again to fulfill a promise with his childhood friend. However, after being infected by a mysterious small kaiju, Kafka himself turns into a kaiju and is labeled "Kaiju No. 8" by the Defense Force he aspired to, becoming their enemy.

This article summarizes the profile of "Kaiju No. 8" creator Naoya Matsumoto and his previous manga works.

Synopsis and Overview of "Kaiju No. 8"

Kafka Hibino, a 32-year-old who once aimed to join the Japanese Defense Force specialized in kaiju extermination, had given up on his dream and worked at "Monster Sweeper," a cleaning company handling the remains of kaiju defeated by the Defense Force. Reno Ichikawa, a newcomer working with Kafka, aspired to join the Defense Force and told Kafka that the recruitment age limit had been raised, meaning Kafka could also take the exam.

Kafka, now determined to aim for the Defense Force once more, gains the power to transform into a powerful kaiju after a mysterious small kaiju enters his mouth. The transformed Kafka is called "Kaiju No. 8" and is seen as an enemy by the Defense Force he wishes to join. Kafka must hide his identity as "Kaiju No. 8" while taking the Defense Force entrance exam.

The manga is serialized on the web comic platform "Shonen Jump+," released every other Friday. In April 2024, the anime began airing on TV, and all episodes are being streamed worldwide in real-time on X (formerly Twitter).

Profile of "Kaiju No. 8" Author Naoya Matsumoto!

Naoya Matsumoto, the creator of "Kaiju No. 8," is a graduate of Asagaya College of Art and Design. Inspired by Akira Toriyama’s manga "DRAGON BALL," he began aiming to become a manga artist and won the 27th Twelve Kings Rookie Manga Award at the "Weekly Shonen Jump’s" Jump Twelve Kings Rookie Manga Awards in 2005. His award-winning work, "Nekoromancer," was published in the 2006 winter issue of "Akamaru Jump."

Matsumoto has stated that he liked kaiju since childhood and used to read kaiju encyclopedias. In interviews, he mentioned being influenced by many manga, notably "PSYREN" by his mentor Toshiaki Iwashiro and "Bobobo-bo Bo-bobo" by Yoshio Sawai. In terms of design, he cites major inspiration from Tsutomu Nihei, creator of "BLAME!" and "Knights of Sidonia."

In the comment section on the cover flap of volume 6, Matsumoto revealed that he keeps a cat in his workspace. He also mentioned that headphones and earphones are his companions while drawing, and humorously wrote, "At my place, headphones and earphones are the hardest-working appliances after the fridge."

Serialization of "Kaiju No. 8" began on "Shonen Jump+" in 2020. Despite all chapters being available for free on the app for first-time readers, the first volume of "Kaiju No. 8" ranked number one in the 2020 "Volume 1 Sales Ranking" for new manga, surpassing titles like "Oshi No Ko" and "Frieren: Beyond Journey's End."

In January 2024, the spin-off manga "Kaiju No. 8 side B," which features episodes of Defense Force members not covered in the main story, began serialization on "Shonen Jump+." Matsumoto is credited as the original creator.

What are Naoya Matsumoto’s Previous Works?

After winning the 27th Jump Twelve Kings Rookie Manga Award in 2005, Matsumoto made his debut with "Nekoromancer," published in the 2006 "Akamaru Jump."

Subsequently, two one-shots, "ROOM STRANGER" and "The Boy Who Became a Witch," were published in "Akamaru Jump." From 2009 to 2010, Matsumoto serialized "Neko Wappa!" in "Weekly Shonen Jump," a story about Tama, a girl raised by a god who aims to become a full-fledged deity.

In 2013, a one-shot version of "Pochi Kuro" was featured in "Shonen Jump NEXT! 2013 AUTUMN," followed by a serialized version on "Shonen Jump+" from 2014 to 2015. "Pochi Kuro" depicts cross-cultural communication between a human girl and a demon who cannot speak her language in a demon world where humans are considered high-class delicacies.

Since 2020, "Kaiju No. 8" has been serialized on "Shonen Jump+." Before this, the four-volume "Pochi Kuro" was Matsumoto's longest-running series, but as of May 2025, "Kaiju No. 8" has become a long-running series with 15 volumes published.

Is There Only One Author for "Kaiju No. 8"?

While Matsumoto is the sole author of the manga "Kaiju No. 8," there are credited collaborators listed on the cover flaps of the comic volumes.

From volumes 1 through 9, credits for production cooperation include Osamu Koiwai (Osa Pro.) for background art, Jiro Sakura for finishing touches, and Mantohihi Binta for firearm design. From volume 10 onwards, Deco has been added as a finisher.

Mantohihi Binta, responsible for firearm design, is a manga artist known for serializing the vertical comic "MQ." Koiwai, the background artist, publishes videos of his work on "Kaiju No. 8" backgrounds on YouTube.

What is the Author’s Gender? Has He Revealed His Face?

From available information, there is no evidence that "Kaiju No. 8" author Matsumoto has revealed his face.

The name gives the impression of a male, but there are cases in the industry such as Daisuke Higuchi ("Whistle!") or Hiromu Arakawa ("Fullmetal Alchemist") who use male-sounding pen names but are female manga artists. Therefore, it's difficult to determine gender based on the name alone.

Does the Author Use Social Media Like X (Former Twitter) or Instagram?

Matsumoto has an X (formerly Twitter) account, where he posts announcements and illustrations related to his serialized works.

When "Kaiju No. 8" won first place in the Web Manga category of the "Next Manga Awards 2021," he posted an illustration and message thanking fans, saying, "It is entirely thanks to all the readers who voted for me."

On January 1, 2024, he posted a New Year-themed "Kaiju No. 8" illustration along with the message, "Happy New Year! Please continue to support Kaiju No. 8 this year!"

Who is the Author of the "Kaiju No. 8" Spin-Off Manga and Novel?

Novels based on "Kaiju No. 8" have been published by JUMP j BOOKS. The title is "Kaiju No. 8: Exclusive on the Third Division," containing four original stories that can only be read in the novel. The author of "Kaiju No. 8: Exclusive on the Third Division" is Keiji Ando. Ando has also written the novelization for the anime "The Magnificent Kotobuki" among other works.

The official spin-off manga "Kaiju No. 8 side B" is jointly based on the original works of Naoya Matsumoto and Keiji Ando (the author of the novel), with the manga illustrated by Kentaro Hidano. Hidanon previously worked as the artist for "ZIGA" (story by Rokurou Sano) and "Super Smartphone" (story by Hiroki Tomizawa), both serialized in "Weekly Shonen Jump."

Matsumoto commented on his X account about Hidanon, saying, "I love the illustrations and manga drawn by Hidano, so it is an absolute honor that he accepted this project! He brings out the charm in all the characters, but especially his version of Kikoru Shinomiya is just... so cute!"

Summary

The author of the manga "Kaiju No. 8" is Naoya Matsumoto, who debuted after winning the 27th Jump Twelve Kings Rookie Manga Award with his work "Nekoromancer."

Aside from "Kaiju No. 8," Matsumoto’s previous serialized works include "Neko Wappa!" (serialized in Weekly Shonen Jump) and "Pochi Kuro" (serialized on Shonen Jump+).

The official spin-off manga "Kaiju No. 8 side B" is based on original drafts by Matsumoto and Keiji Ando, with the manga drawn by Kentaro Hidano.

(C)JAKDF 3rd Division (C)Naoya Matsumoto/SHUEISHA

List of images for this article