Nemu is short, only slightly taller than Konekomaru Miwa, and wears the typical True Cross Academy uniform. His eyes are typically closed, and only open up in times of danger. He wears a puppet on his arm, which he uses to communicate via ventriloquism. Nemu's messy, light brown hair and closed eyes give him a perpetually sleepy appearance.
Nemu is a mysterious individual that keeps to himself. In order to properly act as a hidden moderator for the cram school, he would rarely partake in group activities and would often avoid speaking. When he needs to communicate, Nemu typically uses a sock puppet to talk in a high-pitched voice, and will often address others in a rude manner. He commonly does not show respect for his superiors, and will ignore their questions.
Once his role as a moderator comes to light, Nemu continues to maintain his quiet, eccentric demeanor. However, he is not above putting down the cram school as a waste of time for someone of his skill, indicating a high level of self-confidence.
Interestingly enough, the doll on Nemu's arm seems to have some level of sentiency and control over the young man's body. When Nemu is almost killed by Renzo Shima, the youth's perpetually closed eyes open up, which startles the doll enough to tell the main body to calm down and go back to sleep.
True Cross Academy arc
Nemu first appears when Rin Okumura enrolls at True Cross Academy. He continues to appear in the background and is mentioned several times. While he does not appear more than a few times, he is seen receiving treatment along with the others. He is paired up with Konekomaru Miwa during the search for the ghost in Mepphy Land, but neither of the two are seen until after the whole ordeal when they are all in a group, at which point Nemu still just stands silently in the background.
Training Camp arc
Nemu is later seen during the forest training. He is seen running into the forest and, according to Izumo Kamiki, is the first one back with his Peg Lantern, showing that he is more powerful than he seems.
Impure King Revival arc
Nemu just stands silently in the background. He is, however, mentioned by Shura Kirigakure in a conversation with Mephisto. It appears that Nemu entered into the Academy for a mission, similarly to Shura.
Terror of the Kraken arc
Nemu is seen with the group when they are on the beach trying to have fun and relax although he mainly keeps to himself, citing a stomach ache as to why he is not wearing a swimsuit.
True Cross Academy Festival arc
Following the festival, it is revealed by a captured Illuminati spy that Izumo has been targeted for capture by the organization. Izumo is approached by Nemu and leaves with him to investigate further after he implies he is an Illuminati spy. He later seemingly confirms this to her and they battle with their familiars. Nemu easily overpowers Izumo and is preparing to deal a devastating blow before Renzo Shima intervenes and saves Izumo, revealing himself as a powerful Tamer in the process. Nemu and Renzo battle until Renzo manages to overpower him. Just as he is about to strike the final blow, Nemu's eyes open and meet Shima's. The pink-haired youth is startled enough by mere eye contact that he withdraws from their duel. As his opponent withdraws, the doll on the Tamer's arm tells the main body to calm down and go to sleep. Nemu is present for Shima's reveal as the Illuminati spy, as well as Lucifer's declaration of war against the True Cross Order.
It is later revealed by Mephisto that Nemu is an Exorcist that he hired from "a third party" to monitor the cram school. His current skill level places him as an Upper First Class Exorcist, indicating that he is more powerful than all of the current Exwires. He was assigned by Mephisto to the cram school group to pursue the Illuminati and rescue Izumo.
Nemu is sent along with the rest of the team to Inari Shrine to rescue Izumo. When asked by Konekomaru how he knows that is where Izumo is, Nemu tells him that he summoned and planted a doll on her and he is able to locate any object he summons. Upon arriving at the shrine, Nemu disappears from the group without anyone noticing. After the group does some reconnaissance and regroups, Nemu reappears holding a very expensive fox god puppet that he had bought. He wastes no time in invoking Miketsu into the puppet so that the group may learn more about Izumo's past. 
After Mike Fox God explains everything he knows about Izumo's past and the current situation, the group arrives just outside of the Far East Laboratory. Suddenly, Mike is then summoned and leaves the puppet. Nemu assures everyone and then says that it looks like that he was summoned by Izumo. The group then begins their assault on the laboratory. Once inside, the group encounters a Zombie, which at first they thought was a Ghoul until it spoke. After Yukio and Konekomaru explains the differences between a ghoul and zombie, a large group of Zombies then attacks the group with the one they first encountered reanimating and resuming it's attack. They then begin to fight their way through the zombie horde while searching for an entrance to the underground laboratory. 
It does not take long until everyone is eventually surrounded by the zombie horde. They hastily try to figure a way through the zombies when suddenly, the floor beneath them opens separating and dropping them into the lower levels of the facility. Nemu is then shown to be trapped in a containment cell, similar to the ones everyone else is in. It is then revealed that there appears to be a large group of zombies waiting just outside of each room. Later, going against Lucifers orders, Michael Gedōin turns on the lights to the containment cells and releases the Chimera Zombies into each cell. As the battle rages on, eventually Rin, Shiemi and Konekomaru manage to break out of their containment cells. Rin then uses Satan Bomb to free Yukio, Ryuji and Nemu from theirs. Nemu and the rest then regroup just as Michael Gedōin reveals himself to them over the intercom. As the giant chimera zombie attacks, Nemu is seen running away with the rest of the group. After Rin fails to save Izumo Kamiki and continues his battle against Renzo Shima, Nemu is seen with the rest of the group, cornered by the giant chimera zombie.
Nemu is then seen again later fighting with the group and attempting to hold off the zombie horde while Tamamo Kamiki performs the Divine Summoning to exorcise the Nine-Tailed Fox Spirit from Izumo. Nemu is seen after the battle has concluded, standing silently with everyone after Tamamo Kamiki's death. The next day, Nemu sneaks into Izumos hospital room. He tells her the the order had taken control of the Illuminati's lair and that everything is over. Izumo then says that they have yet to find Tsukumo Kamiki. Nemu scoffs and then alludes that he knows where she is. Nemu then reveals a key to Izumo, telling her that it is connected to Tsukumo and is a get well present from his employer. He then invites Izumo to take a look with her own eyes before handing it to her. stepping through the door, Izumo then see her younger sister is alive and well. Nemu then explains that she was adopted by the CEO of Takara computer entertainment and his now his cousin. He go's on to tell her that the Takara group is owned by Mephisto Pheles and that Tsukumo was kept well hidden and protected. He then tells her the key is hers to keep before taking his leave.
Sometime later, Nemu is seen with the others, resting on the stairs to Tamamo's grave while Izumo visits it.
Exorcist Exam Arc
Nemu is seen sitting quietly at his desk as Rin Okumura enters the classroom disguised as Renzo Shima Even when Renzo himself returns to the classroom not long after, Nemu seemingly ignores him. When Ryuji and the others start confronting Renzo over everything that happened, Nemu still sits quietly at his desk. Even when everyone begins to attack Renzo, Nemu calmly sits, seemingly ignoring them still. Later, everyone is transported to Mephisto Pheles office as Lewin Light carries out an interrogation to determine if Renzo is trustworthy. Nemu sits quietly and does not even speak when Lewin asks them all if they can trust Renzo. Later, Mephisto teleports everyone including Nemu, but not Renzo and Yukio out of his office.
As the others discuss what had just transpired, Nemu seems to quietly slip away unnoticed by the rest. At the bathhouse, Rin seems surprised to see Nemu in the bath with his puppet and asks him if it's ok for him to soak it in hot water. Responding through the puppet, he asks Rin if he is saying if it is wrong for him to enjoy the hot water. Confused, Rin says he was only asking about the puppet. Later, Nemu is shown sitting quietly with Rin sitting with him in the bath while Renzo has an outburst. Later, Nemu is handed the form pertaining to what meister he will be testing for, along with everyone else in class. Later, Nemu is shown in the packed classroom where Lewin Light takes over teaching Shura's Magic circles and Seals class. Even with many students leaving before the end of Lewin's lecture, Nemu is shown to be among those that stayed.
Nemu does not appear in the Aomori Arc.
Powers & Abilities
While his abilities have not been thoroughly explored, Nemu is powerful enough for Mephisto Pheles to hire him as a moderator for the cram school, indicating that he is quite powerful. Mephisto Pheles claims that despite his youth, the Tamer has the skills of an Upper First Class Exorcist and is above the level of most Exorcists.
Nemu refers to himself as a Puppet Master (
- Jean, Groom Version (ジャン 花婿
VerJan Hanamuko Bājon): A fashion doll ( 着せ替えFasshon Dōru) from the Mika Friend Series (ミカフレンドシリーズ Mika Furendo Shirīzu), it is first used to pacify the transvestite ghost.
- Tsukumo Kamiki's Precious Mascot (): A small stitched doll, Nemu summons it to track Izumo Kamiki.
- Mecha Warrior St. Gaia (超機兵 セントガイア Chō-ki-hei Sentogaia): A transforming robot toy (変態ロボット玩具 Hentai Robotto Gangu), it is first summoned at 1/18-scale model (1/18モデル等倍 1/18 Moderu Tōbai).
- Kitchen Knife Bunny (包丁ウサギ Hōchō Usagi): A plush toy (ぬいぐろみ Nuigurumi) rabbit wielding a kitchen knife. Nemu can mass produce a hundred of them at once.
- Mike Fox God (ミケ狐神): Nemu summons Izumo's familiar, Mike, into an expensive puppet from the Inari Grand Shrine. It is used to gather information about and to locate Izumo rather than to fight.
- His name contains the kanji for "treasure" (宝) and the hiragana for "sleepy" (ねむ).
- (In response to Ryuji Suguro's complaint about his lack of teamwork) "Tch! Shut up, you punks! We don't have anything to say to you!"
- (During Rin's and Yukio's fight against Satan) "Then the fifth angel blew his trumpet, and I saw, a star that had fallen to Earth from the sky, and he was given the key to shaft of the bottomless pit. When he opened it, smoke poured out, as though from a huge furnace, and the sunlight and air turned dark from the smoke. Then locusts came from the smoke and descended on the Earth, and they were given the power to sting like scorpions. Their king is the angel from the bottomless pit, his name in Hebrew is Abaddon, and in Greek, Apollyon- the Destroyer." (Anime only)