Ninjas have often been associated with Japan’s feudal past, but what if they hadn’t gone fully extinct and were now instead working in the shadows of modern society? What if there are several competing organizations with ulterior motives that are always looking for an advantage over one another?
That’s the setting Kengo Hanazawa’s Under Ninja manga series takes place in, but the plot instead revolves around the seemingly lazy NEET Kuro Kumogakure, who gets involved in a dangerous ninja assignment.
Anime Trending spoke with Hanazawa at this year’s 2025 Anime NYC for a short interview. In our discussion, we talked to him about the influences of his manga, his unique cast of characters, and how he navigates the manga’s complicated storyline.
What inspired you to feature modernized ninjas working in public and private sectors in Japan? Were there any specific influences that influenced your manga series?
Kengo Hanazawa: When my previous series, I Am a Hero, ended, I was basically in a state where I was really drawing a blank. I had no idea what I wanted to draw about next. As I was discussing with my editor at Kodansha, we were just having some discussions, and they very casually mentioned, “Oh, what about ninjas?” And I thought, “Okay, well, ninjas — I can draw some ideas around ninjas,” and that was basically the start of the series.
As far as influences or inspirations go, there are obviously lots of ninja manga out there, but I do want to point out [that] Kodansha’s Young Magazine serialized a series called Dai Tokyo Ninjyaden Kagerou-kun. It was a very short series, but it really left an impression on me, and I really thought that it presented a premise that I could expand and make bigger in scale.
The Under Ninja manga and anime feature a non-linear narrative that goes back and forth between the past and the present. Why was it necessary to frame the story in that way instead of a traditional linear storyline?
Kengo Hanazawa: The manga has pretty linear storytelling, I think. But when we were coming up with the anime, it had to be changed because the beginning part of the manga is pretty slow. We were worried that dropping the manga’s story into [the] anime exactly as it was drawn would bore the audience a little bit at the beginning because of the slow pace. So, the anime production team really started structuring the story in a way that was a lot more thrilling and exciting from the beginning. And when I saw what they were doing, I was impressed and thought, “They’re doing really good work.”
The manga features an ensemble cast of characters who have unique skills, personalities, and backgrounds. Why was it important for you to feature such a diverse cast in your story?
Kengo Hanazawa: I first started by creating the protagonist, and then I wanted him to do things in the story. I needed him to move and act. But, he basically didn’t want to do anything. He basically refused to act or move, which meant that I had to create a cast of side characters who would act on his behalf and carry the story along until finally, the main protagonist said, “All right, I’ll start working, I’ll start doing stuff.” That’s how I managed to get the flow of the story going and finally get it proceeding in the direction I wanted. To answer your question, I basically had to create a diverse cast of characters to get the story going.
What was it like for you to balance all the different storylines and character arcs in the manga? Do you have ways to organize yourself so you don’t get too confused or lost in the story?
Kengo Hanazawa: I do get confused by the many characters and storylines, but by creating a bunch of different characters and creating a bunch of different storylines, it helps me to sort of coincidentally and serendipitously find a way to work something in later. [I think,] “Oh, that could have been foreshadowing for this,” or a character that I previously created in the story will come in and help me out when I’m in a pinch.
In a way, my work sort of helps me figure out how to organize the various aspects I’ve put into it and saves me. As I mentioned earlier, I’m basically thinking about what would make this story more interesting on the fly as I go, but somehow the things I’ve compiled by thinking about what’s interesting kind of work out. They connect with each other, and they form a coherent story at the end — or at the very least, I have faith that it will.
Interpreter: Mimmy Shen
This interview has been edited for clarity and length.
The Under Ninja manga series is available in English from Denpa. A preview of the series was published in Kodansha’s Young Magazine USA. It was given out at this year’s Anime NYC 2025 and is also available to read digitally on Azuki.
