|Height||159 cm (5'3")|
|Weight||48 kg (106 lbs)|
|School||Kunugigaoka Junior High School|
|Japanese Voice||Mai Fuchigami (Anime) |
Nao Tōyama (OVA)
Nozomi Yamamoto (VOMIC)
Nagisa is a petite framed boy with light blue hair and azure eyes. His hair is shoulder-length because of his mother making him keep it that way, but due to the school having a rule about male hair lengths, he keeps it in two pigtails. He is known for his androgynous appearance which has often poked fun at by many people - most notably, Rio Nakamura.
Nagisa is a calm, collected, and friendly individual. He is exceptionally observant and circumspect of his surroundings and the situations that develop around him. He tends to pay strict attention to Korosensei in hopes to understand the motives of this mysterious being and compiles the information he has gathered in his notes for reference.
Despite his calm demeanor, he harbors deep insecurity about his talents and how he is perceived by the people around him. This is reflected by lack of goals and general pessimism about his own future.
Nagisa is the son of Hiromi Shiota and her (presumably ex) husband. His mother had hoped for a daughter so she could experience all the things she had missed as a child through her, but got a son instead. As a result, she dictated his life from forcing him to keep his hair long, to being forced to crossdress and verbally abused him whenever he spoke against her. Her personality also caused her husband to leave her and Nagisa.
He was revealed to formally have been in Class D during his first two years of middle school before falling into Class E due to poor grades. 
After homeroom is started by Korosensei, Shiota Nagisa gives the command for the class to stand. They all draw their guns, aim and fire at Korosensei while he takes the register. Nagisa listens to the creature lecture the class on their supposedly simplistic plan and demonstrates the effect the special bullets have on him if hit, much to Nagisa's astonishment. Nagisa, along with the rest of class 3-E tidy up the classroom under Korosensei's instructions.
He is present in the class after where Kayano Kaede whispers to him, pointing out the permanent crescent moon in the sky causing Nagisa to remember both the destruction of the moon and the meeting and introduction of the culprit. This happened along with Karasuma from the ministry of defense both explaining and actively showing what their future jobs will be, along with revealing the 10 billion yen reward.
Later, while thinking about how the students of class-E aren't normal students, Terasaka, Yoshida and Muramatsu approach him about working on an assassination plan, which he agrees to do with them.
During Chapter 38, Karasuma-sensei goes under the impression that Nagisa was an average student. However, during training, he felt a strange presence, similar to that of a snakes. Around Chapter 39-42, Takaoka-sensei arrives at Kunagigaoka in order to train the students better against Korosensei, challenging Karasuma to choose one student to attempt to assassinate him, using a real knife. Karasuma decides to choose Nagisa.
In the fight against Takaoka-sensei, Nagisa shows his true talent for assassination, cornering Takaoka-sensei from behind, astonishing his class and completely exceeding Karasuma-sensei's expectations.
- Main article: Karma Akabane
Karma is one of Nagisa's closest friends and the only person Karma will seemingly listen to. They were in the same class for their first two years of middle school which continued into their third year. Unlike many people, Nagisa is unfazed by Karma's violent behavior and although they have basically opposite personalities, they do have similar interests and get along well.
- Main article: Kaede Kayano
Kaede is another one of Nagisa's closest friends and the two sit next to each other in class. Out of all the females, Kaede is definitely the one he's closest to. They get along well and are often seen together and were paired together during the Assassination Test of Courage.
- Main article: Ryōma Terasaka
In the beginning of the series, Terasaka suggested a plan to kill Korosensei, which Nagisa agreed to take part in. Even though the plan itself failed, it was the first suggestion of Nagisa's natural talent for assassination.
- Main article: Tadaomi Karasuma
Karasuma-sensei thought that Nagisa was a mild student with no special physical abilities. However, he did sense the presence of Nagisa's natural talent for assassination. Because of that, he chose Nagisa to challenge Takaoka in a "mock assassination", which Nagisa skillfully won.
Assassination: Nagisa's physical abilities are mediocre, and he is one of the weakest among the boys; not only that, but his constitution and strength is equal to a girl's. However, Nagisa has an extraordinary amount of natural talent as an assassin; as shown in his duels against Takaoka and numerous times during the span of the story.
Bloodlust: In addition to having a hidden, but also disturbingly massive, amount of natural talent for assassination that far surpasses Karma Akabane, perhaps even Tadaomi Karasuma and Irina Jelavic, despite the latter two both being a trained fighter and killer respectively, he also has a frighteningly massive amount of hidden bloodlust that can shake and terrify even the most trained assassins and soldiers. This is most evident during his 'mock assassination' with Takaoka-sensei, as well as when two of Nagisa's old classmates threaten him. This unique talent has sparked the interest of all three of Class 3-Es main faculty. When released, it seems to take the form of a large, blood-soaked snake coiled around Nagisa's target with its fangs bared and looking like it's about to strike.
People Reading/Discernment: Due to his mother's personality, Nagisa developed the ability to read people with ease. After receiving the God of Death's "Clap Stun Attack" this ability later evolves into where he can view the "wavelength" or "wavelength of consciousness" of a person that represents the person's breath, line of sight, expression, and more. This allows him to find a person's gap in consciousness as well as their peak in consciousness which he has used from throwing an enemy off before attacking, to simpler things being able to remove a size label without the person wearing it noticing.
- (About Korosensei) "Chew out at Mach 20, then praised with waving tentacles... This unusual education made me pretty happy. All because this unusual teacher was actually looking at us head-on."
- (About Korosensei) "We've never assassinated anyone before, and there's plenty of other stuff we should be doing. But you know... I think this teacher might even accept my blood lust."
- (To Korosensei) "Before you destroy Earth... I'll kill you."
- (To Akira Takaoka) "I feel that Karasuma-sensei, who devotes himself to being professional, is much kinder than Takaoka-sensei, who forcefully passes off as a father."
- (To 2 Class D Students) "Kill me, huh? And yet it looks like you've never killed someone before."
- (To Kayano Kaede) "I want to know more about everyone, try killing sensei more, and live so I don't leave anything unfinished."
- His favorite food is sushi according to Chapter 2.
- His favorite subject is English while his least favorite subject is Science.
- His hobby is researching.
- He was called "Gender" during class 3-E training using code names.
- Nagisa appears as a Story Mode NPC in the PS3 game J-Stars Victory Vs, along with Irina and Karasuma.
- In the art rankings of Volume 5, Nagisa placed 5th among the male students.
- Nagisa is one of the few people in the entire manga who is referred to by his first name. Considering the last name basis setting, this type of formality is a bit odd.
- In the popularity poll of Volume 12, he was ranked 2nd.
- In the tankobon extras, his statistics were listed as:
- Physical strength: 2
- Mobility: 3.5
- Close-range assassination: 3.5
- Long-range assassination: 3.5
- Academic ability: 3.5
- Characteristic skill: 5 (anti-human assassination)
- ↑ Assassination Classroom 112 page 15-17