Story Arcs
This page is a stub. Please wait for more info to be added.
A list of story arcs for the Oneirosea series.
Table of Contents
Introduction Arc
Hiro Nimura is the latest member of Alcyon Corporation's Offense Division. He has greatly admired the company ever since one of its agents saved his life as a child, and hopes to follow in her footsteps. He is placed on a small team led by Ichika Sasaki, and sent on routine division missions such as training simulations and lesser demon extermination. Between work, Hiro investigates his savior, and is surprised to find that nobody in the company except his coworker Clover has any idea who she is.
While escorting Rishi Aizawa through oneirosea, disaster strikes and the team is stranded in the abyssal zone. They overhear some demons planning a mass invasion of Semikawa, then manage to escape and report this information to the command division.
Midnight Forest Arc
The command division announces that a group of offense agents will soon be chosen to infiltrate the Inverted Castle, in order to slay the demons involved before the changeling invasion can occur. Ichika declares that their team will make it into the group no matter what. Tensions rise as she pushes the others to train beyond their limits. They also come into conflict with Shuhei Samejima and Akemi Himeno, another team aiming for the same position.
Both teams are given a special assignment in order to test their aptitude for the upcoming mission: explore the Pale Forest, a midnight-rank demon's lair. The mission spirals out of control as the rival teams argue over their methods, and the lair's reigning demon pulls the strings to prevent them from leaving.
Inverted Castle Infiltration Arc
Along with Akemi Himeno and Shuhei Samejima, Hiro's team is chosen for the infiltration. They arrive at the Inverted Castle, but the demons found there are much more dangerous than initially expected, as the masterminds had recruited a number of hadal- and benthic-rank demons to serve as guards. Their cover is blown when a guardian demon attacks, separating the members and scattering them throughout the castle. Each member of the group then has to make their way to the center of the castle to regroup, leading to a series of parallel one-on-one matches.
Hiro and Ichika face off against the demon Laplace, who identifies Hiro as a "traitor", confusing him greatly. The two are overpowered and nearly killed, but Hiro appears to manifest a second unique power at the last moment and defeats the demon before collapsing. The infiltration team members are rescued by the Benthic Strike Team.
Changeling Invasion Arc
The arc begins with Hiro in the hospital, recovering from his injuries. Coincidentally, he encounters his childhood friend Nanami Murakami there, and the two catch up. Meanwhile, Ichika demands answers from her higher-ranked connections regarding the seemingly-planned failure of the infiltration mission. However, she is repeatedly ignored or brushed aside, being told that everyone is too busy preparing for the upcoming invasion.
Despite Alcyon Corporation's efforts, most of the changelings arrive in Semikawa City as planned. Clover, Ichika, and Hiro (who had mostly recovered) join the rescue efforts, learning to exorcise changelings on the fly.
Labyrinth Arc
Labyrinth, Alcyon's rival megacorporation, uses the aftermath of the invasion as an excuse to criticize and undermine Alcyon Corporation's reputation. Meanwhile, Ichika is transferred to the defense division, and Hiro is left in charge of the team. He struggles to keep the team together and maintain normal operations, while dealing with public criticism and his strange new abilities at the same time.
As time goes on, Labyrinth becomes bolder. The company eventually announces a new project to reduce oneirosea's size by venting its mist into reality, to the support of the general public. Alcyon Corporation warns that this project will damage the fabric of reality, but this is written off as anti-Labyrinth propaganda due to their poor reputation. With no other options, Alcyon agents must directly confront Labyrinth and stop their plan by force before it comes to fruition.
Goodwill Festival Arc
After the events of the Labyrinth Arc, Alcyon Corporation holds a free-to-attend festival for the entire town in order to re-establish friendly relations. The star attraction is the Alcyon Corporation Inter-Division Tournament, a recurring televised event that is very popular among the offense and defense divisions due to their longstanding rivalry. Relieved for a chance to put his worries on hold in favor of some low-stakes festival games, and hoping for a chance to face Ichika in battle, Hiro signs up for the tournament. However, she is not among the registered participants, and in fact seems to be avoiding her former teammates when they seek her out between battles.
Hiro makes his way through the tournament, quickly becoming a fan favorite, but struggles more and more to ignore the artificial and crowd-pleasing way the event is designed. While waiting for the semi-finals, he spots Ichika and demands she explain her behavior to him. She insults him for trusting Alcyon Corporation so blindly despite the evidence, and giving up on his search for the mysterious woman in favor of cheap fame. Their argument escalates into a physical battle.
After the fight, Ichika reveals that she has applied to transfer back into the offense division, having missed the team and found the PR-obsessed culture of the defense division distasteful. Hiro is disqualified for missing his match, but he feels renewed in his purpose.
Nautilus Vault Arc
In order to learn more about Hiro's mysterious powers, the squad returns to the Inverted Castle to confront Laplace, the demon who seemed to recognize him as someone else during the castle infiltration. Laplace agrees to give them the information, in exchange for a number of diel shells from Alcyon Corporation's vault. Hiro and his team must find a way to steal these shells from beneath the company's all-seeing surveillance.