Nochizawa Eiji

Nochizawa Eiji (後沢 鋭二), known as Nautilus (ノーチラス) in Sword Art Online (SAO) and Eiji (エイジ) in Ordinal Scale (OS), is one of the antagonists of Ordinal Scale and one of the main characters of the Ordinal Scale side stories, including Hopeful Chant and Cordial Chords. He was the childhood friend of Shigemura Yuuna (Yuna), and was one of the 10,000 players who were trapped in Sword Art Online, where he suffered from a FullDive Non-Conformity condition that impeded his movement whenever he feared for his life. Despite his condition, Eiji as Nautilus managed to be recruited by the Knights of the Blood due to his levelling progress; however, after his condition endangered his party during his first battle against a mid-boss, he was forbidden from taking part in the 40th Floor Boss battle. On the day of the boss battle, he led an emergency rescue party to aid a party of players who became trapped in a boss room inside a field dungeon. This rescue attempt resulted in the death of Yuna, thus, in the aftermath of the incident, Nautilus left his guild and secluded himself in an inn on the 1st Floor for the remainder of the game.

Background
Unbeknownst to Eiji, he was the second son in his family; however, his parents divorced while he was young, splitting custody over their children. While his father took custody of his elder brother, Eiji continued living with his mother as she married for a second time.

Since then, Eiji lived in the same neighbourhood as Shigemura Yuuna and went to the same kindergarten, and school as her until she enrolled in an all-girls high school. Despite having developed feelings for the girl in kindergarten and being good friends with her, the boy was unable to convey his feelings to her. Hoping that he might be able to confess how he felt about her in a virtual world, Eiji invited her to play Sword Art Online together; to his surprise, the girl accepted his invitation. With the help of Yuuna's father, the two managed to acquire two copies of the game and logged in on the first day, becoming trapped in the death game. On that day, Nautilus promised Yuna that he would ensure her safe return to the real world and began working on a way to achieve that goal.

Having heard of multiple players who had lost their lives due to careless mistakes by overestimating their strength, Nautilus decided to act cautiously and thus spent the first six months of his time in Sword Art Online practicing the use of Sword Skills in a deserted training field at the outskirts of the Town of Beginnings to increase the level of his One-Handed Sword skill without exposing himself to danger. Having unlocked «Horizontal Square» after six months of diligent practice, Nautilus finally left the safety of town. Ever since his first real battle, Nautilus discovered that his body would become somewhat unresponsive to his commands whenever he felt he was in danger.

Unbeknownst to him, this state was caused by a form of FullDive Non-Conformity. In Nautilus's case, the NerveGear had a defect in converting his motor commands to in-game motions whenever different sites of the brain generated conflicting commands. While the person's neocortex, responsible for higher-order brain functions such as reasoning, would normally override the signals generated by lower brain centres, such as the ones responsible for instinctive behaviour, the NerveGear was instead giving more priority to the commands from his lower brain centres. Thus, whenever Nautilus felt that he was in danger, he would have difficulty overcoming his instinctive reaction to avoid danger, even to the point where his body would become petrified in place by fear.

However, Nautilus was seemingly able to overcome his fear due to the self-assurance he acquired through his possession of Sword Skills with power far greater than normal for his current level. As such, he was able to engage in rapid levelling with the help of his Sword Skills and soon reached the ranks of players able to fight on the front lines. At some point, he was scouted by the Knights of the Blood and invited to join the guild. At first, Nautilus became a member of the guild's Second Army, but around the time the 40th Floor was reached, Nautilus was promoted to the First Army and allowed to participate in Labyrinth battles.

Hopeful Chant
On October 15, 2023, Nautilus joined Asuna's party in the First Army of the Knights of the Blood to defeat the Ruthless Warder Chief, a mid-boss blocking one of the stairs in the 40th Floor Labyrinth. However, an episode of Nautilus's FullDive Non-Conformity was triggered by the sight of the boss, making him unable to respond to Asuna's commands. Thus, during Asuna's party's turn to engage the boss, Nautilus's absence left Sanza, a member of Asuna's party whom he had to support with his shield, vulnerable to the boss's area attacks. While casualties were avoided in the battle, Sanza's spear was broken by the boss, thus when the raid group returned to Jaileum, the main town on the floor, Nautilus, reluctant to return to the guild headquarters as he shared a room with Sanza, rented a cheap inn room. After venting his frustrations by attempting to stab his knee in vain, Nautilus received a message from Yuna, informing him that she had come to meet him, and thus left the room.

Having arrived at the Teleport Gate plaza, Nautilus found and approached Yuna. The boy was unable to hide his dejected state from her, thus he had to inform the girl of his blunder earlier that day. As her way of comforting him, Nautilus received a piece of candy from his childhood friend, while being reassured that the guild would forgive his mistake. Nautilus was then taken by the girl to a nearby orchestra, where she sang him a song to brighten his mood. As the two-minute-long song attracted a large audience, Nautilus had to follow the girl as she escaped the plaza to avoid the unwanted attention. Having been taken to an empty corner through the narrow back lanes, Nautilus's praised the girl's song and learnt that she had always preferred singing to playing instruments but could not bring herself to share her interest with her father. During their conversation, the boy noticed that he had acquired a buff and thus discovered that his friend had an Extra Skill called Chant that granted various buffs through songs. At that point, he also learnt of the girl's hopes to be able to use the skill to support the Clearers on the front lines.

The following day, on October 16, 2023, Nautilus was summoned to the guild commander's room, where he was informed by Asuna that he would not be allowed to take part in the upcoming Floor Boss battle, despite his pleas for her to reconsider. Upset by this decision, the boy rushed out of the guild headquarters and secluded himself in the same inn as the day before, after spending the day wandering the town. There, he discovered via a guild announcement message that the boss room had been found. Two days later, on October 18, Nautilus came to Jaileum in disguise to watch as the raid party used a Corridor Crystal to travel to the boss room without being identified. Once the last member of the raid party stepped through the portal, the boy was about to leave the plaza, when he was unexpectedly approached by Yuna, who had been worried about him due to him not responding to her messages. As the girl realised that Nautilus was not allowed on the boss raid party, the boy was invited to join the girl for a meal in the town.

While they were discussing Yuna's desire to join the Clearers at an open-café near the western gate of the town over a meal, Nautilus and Yuna heard a player pleading for assistance. Upon learning that the player's party was trapped in a field dungeon and being assaulted by a group of monsters, Nautilus formed an emergency rescue party from the higher-level players in the area who volunteered to help when he requested the help of two Fuurinkazan members on the scene. To Nautilus's surprise, Yuna firmly declared her decision to join the rescue party before the boy could say anything to dissuade her, thus he had no choice but to allow her to join the rescue attempt. After departing through the western gate moments later, the ten-member rescue party reached the field dungeon and arrived at the cell with the trapped players in approximately eight minutes since leaving the town.

Inside the cell, Nautilus saw the five trapped players battle against a group of demi-human infinitely respawning monsters, while the dungeon's boss, the Feral Warder Chief, was blocking the lever that controlled the bars blocking the path connecting the room to the rest of the dungeon. Having analysed the situation, Nautilus concluded that defeating the boss was the most logical way to safely rescue the players from the room, as opening the doors would cause the boss to join the battle, making it hard for the entire party to safely leave the room before the bars closed again. Due to Yuna supporting Nautilus's plan with one of her songs, all the players in the area were filled with renewed enthusiasm, allowing them to proceed with the plan.

Once inside the room, Nautilus charged at the boss with his «Rage Spike». Having drawn the attention of the boss, Nautilus ordered the party of the trapped players to occupy the boss's minions, while he and the Fuurinkazan members drew the attention of the boss to allow the remaining members to deal damage to it. Although the first eight minutes of the battle proceeded according to Nautilus's plan without any issues, once the boss's final Hit Point bar entered the red zone, a large number of minions began swarming into the room, overwhelming the party in charge of distracting the minions. Before Nautilus could adjust the party's strategy to support the players in peril, the boss activated an area attack that Nautilus and the others had no knowledge of, paralysing almost all of the members fighting the boss with the surprise attack, except for Nautilus, the Fuurinkazan members, and Yuna.

With most of the boss party incapacitated and the minion party unable to use crystals due to suffering a Silencing debuff, Nautilus, unable to think of a different solution to the dire situation, was about to ask Yuna to escape with him by using a Teleport Crystal. However, Nautilus instead witnessed Yuna rejecting the idea without even allowing him to propose it, before rushing to the aid of the minion party. To Nautilus's horror, his childhood friend used one of her songs to draw the attention of all the minions to herself to relieve the other players. In panic, Nautilus attempted to plead the two Fuurinkazan members restraining the boss to come to Yuna's aid; however, his plea was rejected by the two men, who choose to prioritise defeating the boss first. With no one else to help, Nautilus resolved to rush to Yuna's aid himself, regardless of the consequences. However, at that very moment, Nautilus's fear overwhelmed his ability of reason, freezing his entire body in place. Despite his desperate attempts to get his body to move, the boy could only watch in despair as Yuna threw her bottle of candies to him, before dying at the hands of the minions just as the boss was defeated.

In the aftermath of the battle, Nautilus resigned from the Knights of the Blood and secluded himself in the 1st Floor inn that he had been living in with Yuna during the first days of the death game, recalling Yuna's final moments time after time while agonising about what could have been done to avoid the tragedy. After half a year of such thoughts, the boy began to blame other members of the rescue party, especially the two Fuurinkazan members who rejected his pleas for help, for Yuna's death. With time and hearing of Fuurinkazan's contributions in progressing through the game, the boy's hatred for the two members expanded to include the remainder of their guild, as Nautilus spent the remainder of the game in his seclusion.

When the game was finally cleared on November 7, 2024, Eiji found himself in a hospital in the care of Yuuna's father, Professor Shigemura Tetsuhiro. At that point. Eiji learnt the truth about his parents, his mother's second divorce, as well as the fact that Yuuna had indeed died in the real world, shattering Eiji's last hopes that she may have been spared by Kayaba Akihiko. Two days later, Eiji was visited by his mother and step-father, but as the two had started new lives and both were reluctant to bring the child to their homes. As such, Eiji decided to live alone, receiving a sufficient allowance from his parents to rent a cheap apartment of his own. Eiji then made use of the SAO Incident Victim Relief Programme to obtain a high school diploma through a correspondence course but lacked the motivation to continue his studies at a university, thus he returned to living his life in despair, secluded in his apartment. The dreariness of his days lasted until in the autumn of 2025, he was contacted by the Professor with a request to help his plan to restore Yuuna as an artificial intelligence. With this goal giving him new-found motivation to live, Eiji once again began studying and joined Professor Shigemura's laboratory as an auditing student.

Cordial Chords
Two days following the incident at the New National Stadium, on May 1, 2026, Eiji surrendered himself to the police in Yoyogi, confessing about having injured the members of Fuurinkazan several days earlier. He was detained at the Yoyogi police station until May 7, when he was released without indictment due to none of the Fuurinkazan members pressing charges against him. Reluctant to return to his dreary days in his apartment, Eiji deliberated wandering around town to avoid this, when he encountered Kirigaya Kazuto at the entrance to the police station. Eiji reluctantly agreed to Kazuto's request to visit a restaurant to speak in private, where the former was informed of a distress message the latter had received through a YUNA mascot application on his Augma. While not entirely believing Kazuto's words, Eiji agreed to help him gain access to the Sword Art Online server due to the possibility of Yuna still being on the server and in need of assistance.

Trivia

 * Eiji did not exist in the original draft for the Ordinal Scale movie scenario. Instead, he was added to the story after Director Itou reviewed the initial manuscript and felt that the story needed an additional antagonist.
 * Nautilus was first mentioned as a character in Material Edition 17, which was written before Ordinal Scale. In the Material Edition, Nautilus was still a member of the Knights of the Blood in 2024; however, this was retconned in Hopeful Chant, where Nautilus resigned from the guild in October 2023.