Kaiju No. 8, created by Naoya Matsumoto, broke the traditional shonen tropes by introducing adult characters to be the faces of the Kaiju No. 8 franchise, and is one of the major reasons behind the success of this modern shonen title. If you have been following Kafka Hibino’s journey to exterminate the kaijus, you must be curious about the ages of your favorite Kaiju No. 8 characters. Discover how old the Kaiju No. 8 main characters are, including Kafka, Kikoru, Reno, etc., here in our guide.
How Old Are the Main Characters in Kaiju No. 8?
Before we get started, remember that the author Naoya Matsumoto has revealed only some of the main characters’ ages in the story. Thus, we have estimated the ages of the rest of the characters based on their descriptions in the Kaiju No. 8 series. Without any further ado, let’s find out the ages of the main characters in Kaiju No. 8:
1. Kafka Hibino – 32 Years Old
No matter what shonen title you may pick up to watch, such as One Piece, Naruto, Bleach, etc, you will always find an aspiring teenager as the main character of the series. However, that is not the case with Kaiju No. 8, where Kafka Hibino, the protagonist, is a 32-year-old guy questioning his life choices. Don’t get me wrong, Kafka Hibino is one of the uniquely inspiring heroes, as he chases after his dream, i.e, to stand alongside his childhood friend and protect the world from kaijus even in his 30s.
2. Reno Ichikawa – 18 Years Old
There is always a deuteragonist character who wholeheartedly supports the protagonist in a shonen title, and it’s Reno Ichikawa in Kaiju No. 8. Unlike his best friend, who is in his 30s, Reno Ichikawa is just 18 years old and strives hard to become an elite officer among his peers in the Defense Force.
3. Kikoru Shinomiya – 16 Years Old
The main trio of a shonen title is incomplete without a fierce female character, and Kikoru Shinomiya fills this spot in Kaiju No. 8. Kikoru is confirmed to be 16 years old, which makes her the youngest main character in Kaiju No.8. Don’t mistake her as a young kid as Kikoru is one of the best combatants in the Defense Force.
Moreover, she is the daughter of Isao Shinomiya, the director general of the Defense Force. Kikoru has a complicated relationship with her father, but yearns to become one of the powerful officers to carry on her late mother’s legacy.
4. Mina Ashiro – 27 Years Old
Remember Kafka’s dream? It was to stand alongside his childhood friend, who is a big shot in the Defense Force. It is none other than Mina Ashiro, the captain of the Defense Force’s Third Division. Mina Ashiro is 27 years old, a few years younger than her friend, Kafka, but they share the same dream of wiping out the monsters from their world.
5. Soshiro Hoshina – 25-29 Years Old
Soshiro Hoshina, the vice captain who leads the Third Division alongside Mina, steals the spotlight every scene he is in, like Levi from Attack on Titan. Soshiro Hoshina has not been disclosed by the author in the story, but fans believe he should be around the same age as his captain, Mina, i.e., 25-29 years old. Soshiro aims to prove his strength against the people who deemed him unfit.
6. Isao Shinomiya – Around 50 Years Old
As I mentioned earlier, Isao Shinomiya is the father of Kikoru Shinomiya and works as the Director General of the Defense Force. As he is the father of a 16-year-old character in the series, Isao Shinomiya is expected to be in his mid-50s in Kaiju No.8. Isao fights with everything he can get to preserve the future of humanity.
7. Kaiju No. 9 – Age Unknown
Kaiju No. 9 is the primary villain of the Kaiju No. 8 series. This alpha kaiju was a harbinger of destruction and could take on any human form. As this kaiju’s origins remain unknown, we couldn’t estimate its age. However, it is implied that it has been around for a long time.
8. Gen Narumi – 27 Years Old
Kaiju No. 8 never ran out of the coolest defense officer characters idolized by fans, and Gen Narumi easily tops this list. He is famed as the “Strongest Anti-Kaiju Combatant in Japan” for a reason. Gen Narumi made his debut very recently in season 2 of the Kaiju No. 8 anime.
Since Gen and Mina are classmates and enlisted for the Defense Force at the same time, Gen is speculated to be 27 years old, the same age as Mina. As one of the strongest officers and a gamer, Gen Narumi remains extremely popular among the fans of the series.
9. Iharu Furuhashi – Around 19 Years OId
Mina Ashiro was a savior for many lives, including Iharu Furuhashi, as the captain, who once saved a kid, Iharu, during a Kaiju attack. This ignited the spark inside Iharu, and he became a Defense Officer just like his hero. Iharu Furuhashi’s age hasn’t been revealed in the story, but he is said to be at least 19 years old, as he is confirmed to be older than Reno.
10. Aoi Kaguragi – Around 19 Years Old
Aoi Kaguragi is one of the prodigies who joined the Defense Force along with Kikoru, Reno, etc. However, he has an interesting backstory as a prospect for the Japan Ground Self-Defense Force (JGSDF), but he sacrificed that promising future and enlisted in the Defense Force instead. Since Aoi is also one of the newcomers to the Defense Force, he is expected to be 18-19 years old.
11. Haruichi Izumo – 18-20 Years Old
Haruichi is the heir to the Izumo family, one of the wealthiest families in Japan. They run the Izuma Tech company, the biggest anti-kaiju arms manufacturer in the nation. Despite being the successor of a rich household, Haruichi became a Defense Force officer in the Third Division and risked his life to protect the people. Haruichi’s age has also not been disclosed by the creators. If we are to make a guess, Haruichi should be 18-20 years old, the same as his rival Aoi.
12. Hakua Igurashi – 18-20 Years Old
The Second Division captain, Jura Igarashi, recommended Hakua, her younger sister, to enroll in the Defense Force. As a result, Hakua was also seen among the newly joined officers, Kafka, Reno, and many more. While Hakua and her sisters’ ages remain unknown, Hakua is predicted to be 18-20 years old, as she is as old as the rest of her comrades.
Kaiju No. 8 manga officially ended in July 2025. A few character details were left unanswered by the author, as you can see majority of the main characters’ ages haven’t been revealed at all. Having said that, who is your favorite character in Kaiju No.8? Let us know in the comments below.
Shashank Shakya
