The True Identity of the Cat in “Under Ninja”: Nekohei! Exploring Relationships with Saruta and Juro from Their Ninja School Days


Unraveling the mysteries of Nekohei in the popular manga “Under Ninja”! Serialized in Kodansha’s “Weekly Young Magazine” and currently adapted into a television anime, “Under Ninja” by Kengo Hanazawa stands as one of the most topical manga series. The cat character, described as “cute and mysterious,” has garnered attention. In this article, we delve into the true identity of Nekohei, affectionately nicknamed “Shinobu” and “Nuime,” exploring his past during ninja school days and his connections with Saruta and Juro.

The Cat’s True Identity in “Under Ninja” is Nekohei

“Under Ninja”: Overview

In this article, we focus on the mysterious cat appearing in the manga “Under Ninja.” This cat, living in the house of the protagonist, Kurokumo Kyujiro, was referred to as “Shinobu” or “Nuime.” We will explore the cat’s true identity, touching on its days at the ninja school and its relationships with Saruta and Juro. But first, let’s introduce some basic information about “Under Ninja,” followed by a brief overview and synopsis of the series.

  • Overview of “Under Ninja”

“Under Ninja” is a manga by Kengo Hanazawa, serialized in Kodansha’s “Weekly Young Magazine” starting from issue 34 in 2018. As part of its media mix, a TV anime was broadcast from October to December 2023 on TBS Television and others.

  • Synopsis of “Under Ninja”

With the dissolution of the Pacific War, ninja organizations were forcibly disbanded by the GHQ. However, many ninjas resisted the GHQ’s organizational restructuring and went underground, continuing their activities as UN (Under Ninjas). This UN has been a formidable organization, evading the ninja detection network for over 70 years, yet some ninjas ended up jobless, living a NEET-like existence. Kurokumo Kyujiro finds himself as the leader of Under Ninjas, facing a one-on-one battle at the ninja school.

The Cat’s Nicknames: Nuime and Shinobu

Now, let’s shift our focus to the main theme of this article, the “cat” in “Under Ninja.” This cat graces the back cover of each volume of “Under Ninja,” becoming a sort of mascot for the series. It has settled in Kyujiro’s apartment and is named “Shinobu” by another apartment resident, Kawado. Due to the seam from its head to its back, it was named “Nuime” by a pure-hearted elementary school student living in Korpo Murayama.

In reality, “Nuime” is actually “Nekohei,” a former lower-ranked ninja who attended ninja school. Nekohei (Nuime), with its distinctive upturned eyes, developed its own cat language for communication. It was also the best friend of the runaway ninja Saruta, both of whom ended up as errand boys for Kurokumo Juro. Additionally, Nekohei has caused displeasure by confessing in cat language to Suzuki and Onikubi. Given its development of a cat language, it must have been a significant cat lover originally.

Was Nekohei’s Brain Transplanted into a Cat?

There was an incident during the TV show “Ossan to Issho” involving Nekohei. Nekohei is a clone of Kurokumo Kyujiro and was targeted by Nijiro, the strongest ninja of the Kurokumo clan. Although Nekohei was severely injured, he managed to survive and was chosen as a subject for an experiment due to his strong vitality. His brain was transplanted into a cat’s body by Shin Research. The stitches from his head to his back are evidence of this transplant surgery.

In “Under Ninja,” Nekohei occasionally remembers his human days, feeling resentment towards the Kurokumo clan who tried to take his life, or even converses with Saruta using cat language. However, his thoughts soon become vague, and he reverts to the intelligence of a cat. Additionally, Nekohei’s eyes are prosthetic, equipped with cameras.

Nekohei’s Ninja School Days and His Relationship with Saruta and Juro

This section explores Nekohei’s time at ninja school in “Under Ninja,” his relationship with Juro, and why he was sold to Shin Research. During his ninja school days, Nekohei, along with his best friend Saruta, was exploited as a minion by Juro. Flashback scenes show Juro communicating with Nekohei in cat language, which Nekohei praised as authentic enough to make him a cat. However, it was revealed that Juro was the one who sold Nekohei to the ninja organization.

The ninja organization was searching for a man with a high affinity for cats, and Nekohei’s name came up. When they reunited, Juro expressed surprise and pleasure that Nekohei survived the extreme surgery performed by Shin Research. Outraged, Nekohei confronted Juro for selling him to Shin Research, but when Juro mentioned there was a way to turn back into a human, Nekohei’s attitude changed dramatically. Since then, Nekohei has been seen riding on Juro’s shoulder, conversing in cat language.

Nekohei and Saruta’s Relationship

As previously mentioned, in “Under Ninja,” Nekohei and the renegade ninja Saruta are best friends. Let’s delve into their reunion and the scene where Nekohei goes to save Saruta.

  • Spoiler 1: Reunion with Saruta

In “Under Ninja,” Nekohei unexpectedly reunites with his old ninja friend, the runaway ninja Saruta. Although Nekohei had already transformed into a cat, he used his keen sense of smell to find Saruta and spoke to him in cat language. Saruta was surprised to discover the cat’s true identity but began to share his recent experiences with Nekohei.

  • Spoiler 2: Nekohei rides a motorcycle to save Saruta

Nekohei, who had loved motorcycles even when he was human, still maintains his riding skills despite now being a cat. Deciding to save Saruta during an attack on Kodan High School, Nekohei jumps on a motorcycle and heads towards the school. However, he reverts to his cat intelligence along the way and fails to find Saruta’s location.

Eventually, Nekohei sets out on a mission to rescue Saruta with a sense of purpose. He activates the camera in his prosthetic eye and dashes through the collapsing school building, recording the brutal actions of NIN and the final moments of the students. The footage spread online, exposing the relationship with UN, although Nekohei himself had no idea to whom the video data was sent.

Under Ninja’s Cat (Shinobu) Voice Actor

Toru Nara’s Profile

In junior and senior high school, Toru Nara aimed to become a teacher of earth sciences but eventually decided to pursue a career in voice acting. While working for a company, he attended the Japan Narration Acting Institute and the workshop Talk back training school hosted by Kenyu Horiuchi. After making his voice acting debut, Nara has appeared in numerous works, including TV anime and foreign movie dubs, while also being active in CD dramas, radio dramas, and narrations.

Toru Nara’s Main Roles

Next, let’s introduce the main works and characters voiced by Toru Nara, who played the role of Nekohei (Shinobu) in the anime “Under Ninja”. Born on May 7, 1972, in Shiraoka City, Saitama Prefecture, Toru Nara is a male voice actor currently affiliated with Kenyu Office. Known for his strong husky voice, he often portrays young male characters.

  • “Chihayafuru” (Masayuki Nishida)
  • “My Hero Academia” (Rikido Sato/Snipe)
  • “Ace Attorney” (Masashi Yahari)
  • “Yo-kai Watch” (Kuma <Gorota Kumashima> and others)
  • “BECK” (Yuji Sakurai)
  • “Cardfight!! Vanguard” (Naoki Ishida)
  • “Terra Formars” (Alexander Asimov)
  • “Zoids Wild” (Caviar)
  • “Dragon Quest: The Adventure of Dai” (Frezard)
  • “Inazuma Eleven” Series (Sakichi Shishido, Daichi Amagi, and others)

Under Ninja’s Nekohei Summary

In this article titled “The True Identity of Under Ninja’s Cat is Nekohei!”, we’ve explored the titular topic, including Nekohei’s days in ninja school, his relationships with Saruda and Juro, and the cat’s nicknames “Shinobu” and “Nuime.”

In “Under Ninja,” Nekohei resides in the apartment of the protagonist, Kurokumo Kyuro, known by nicknames “Shinobu” or “Nuime.” However, his true identity is that of a former lower-ranked ninja, “Nekohei,” essentially a human. An incident during his appearance on the TV show “Together with Old Man” led him to become a test subject for the ninja research institute, resulting in his brain being transplanted into a cat’s body. The stitch marks from his head to his back are evidence of the transplant surgery.

Occasionally, he remembers his human past, but quickly his mind becomes hazy, reverting to a cat’s intelligence. Nekohei and the rogue ninja Saruda were inseparable friends, both becoming underlings for Juro Kurokumo. Notably, the cat’s eyes are prosthetic, fitted with miniature cameras for espionage.

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