Osoro is the leader of the school's gang of Delinquents. Very little is known about her past, or her goals. She has been known to be violent, so most people tend to stay away from her out of fear. Osoro will be absent from school for a very long time, and will not make her appearance until the eighth week of gameplay. Against all odds, she will develop a bond with Senpai, who normally keeps his distance from people like Osoro. Senpai and Osoro are polar opposites - so, what kind of experience could possibly cause them to form a friendship? What does Senpai know about her? What does he see inside of her? And what could stop their friendship from blossoming into something deeper?

Royce and Royce is a student at Tracen Academy. A smart umamusume that excels at working independently. In order to become the "strongest" umamusume, winning over people's hearts, she diligently studies how to appeal to fans in addition to her racing. In front of fans, she acts hardworking, but does not let that character show for others. She is truly a demon of self-production..

Hishi Miracle is a student at Tracen Academy. Hishi Miracle can be best described as an umamusume who does her best but is happy with whatever she ends up achieving. While she wants to live up to the public expectations of a typical umamusume as best as she can, there are times where she just wants to slack off instead. Despite this, she may be able to pull off a "miracle" one day. That time will eventually come.... maybe.

She is a student at Tracen Academy. A bright and cheerful Umamusume known for her amazing luck. Her knowledge of feng shui is second to none, and she uses it to navigate not only her daily life, but also her approach to training and races. She insists on making those around her happy with the power of feng shui, and her advice for attaining good fortune is highly sought after.

Rhein Kraft is a student at Tracen Academy. Bright and cheerful, Rhein Kraft's favourite thing to do is to bask in the sun's warmth at any opportunity. She yearns for the Triple Tiara races, which she holds a passionate admiration for, and wishes to go for them, thus working hard every day for that dream. While stubborn to a fault and extra dynamic, she is usually easygoing and makes everyone around her feel relaxed.

North Flight is a student at Tracen Academy. North Flight is Tracen Academy's resident fashionista, an umamusume who loves dressing up in everything and everything! She sticks by the motto that "Any material can shine depending on what it looks like and how it's worn", something that she has experimented with based on her own experience and body size. "Fu-chan's Fashion Advice" is very popular among the school's umamusume.

Naoto Shirogane is the fifth generation of the famed Shirogane detectives, Naoto arrives in Inaba to help investigate the murders, and enrolls as a first-year student at Yasogami High. At first, this seriousness is rigid, unnatural and stubborn due to her secluded nature. This causes her to have trouble getting along with others by adamantly shutting them off, but even then she's not being taken seriously by those she wants to be acknowledged by as she comes across as trying too hard to be an adult. She rarely jokes around which can make her seem like a killjoy or party pooper when the team is involved in silly antics. In Arena, Kanji calls her out on this, saying she is too "uptight" and it makes her seem distant and on a different wavelength. She does get annoyed by the laidback nature of others, responding either with dry annoyance or brushing them off entirely. School. In reality, Naoto has been bound by labels and stereotypes that compromised her identity and sense of relations. As such, she would end up losing herself within her age group, and it even compromises the genuine passions she has as a detective due to her title. All of that would not only make her sheltered from others, but she would become a kind of a workaholic when it comes to her job. Much of her troubles stem from having no reason to be who she truly is, causing her to forget her true feelings, even actively ignoring them. Instead, she tries to fill the hole in her heart by seeking acknowledgement. This has led to a lack of friends and while she does not show it often, she desires for friendship and a sense of belonging. As she bonds further with the team, she warms up considerably. In Arena, she notes the surprising difficulty in trying to balance her detective work with her newfound friends. In fact, she even expresses concern that she keeps putting work before time with them, showing how much her relationships with them have become to her.

M3 is an elite operator of Endfield Industries responsible for carrying out combat missions of the highest secrecy and utmost danger, as well as one of the executors of the Zeroth Directive within Endfield Industries on Talos-II. Recent narrative updates reveal that M3 shares a profound, secretive history with the Endministrator. M3 deliberately maneuvered the Endministrator into the rank of a common operator. She did this so they could experience the true, unfiltered life of Talos-II firsthand, forge their own worldview, and gain the freedom to choose their path when major systemic conflicts arise.

Leticia "Lettie" Garcia is the medic of The Hex. Albrecht Entrati's experiments turned Lettie into a Protoframe, a partial Warframe that still retains their humanity. Lettie possesses Trinity traits. Lettie met Arthur while both were stationed in the same base, with her acting as the field medic of her unit in the Libertatian Army. With her and Arthur as the only survivors in battle, Lettie treated Arthur's wounds and joined the International Crisis Response (ICR) alongside him, Aoi, and Quincy. She has a fondness for animals and owns four rats named Vaquero (cowboy), Anita (named after a friend back home), Neenah (a deceased friend), and Tláloc (an ancient god of rain). Lettie was one of the first volunteers that came forward to Dr. Entrati's offer to receive more than healing. They were then infused with a Helminth serum from Albrecht's time, which in turn morphed and alchemized them into partial Warframes. Their bodies became newly attuned to the Void, whilst their minds were kept intact. Repeated samples were taken from the now-transformed volunteers by Albrecht himself. It was implied by the doctor himself that their humanity may not last, and that it may be only a matter of time until the Helminth finally swallows them whole. As a pet lover, she keeps a small group of rats with her as her pets, citing that her family didn't have a lot of money growing up, having to move from place to place. She is quite fond of the mention of the Cavia gaining intelligence and sentience and becomes angry when she learns that Entrati abandoned them. However, she doesn't trust Kalymos due to her being Entrati's former pet and worrying she might be spying the Hex or plotting to attack her rats.

Hana Daidaiyama suffers from a severe inferiority complex that stems from several incidents in her past. She is deeply insecure about herself - everything from her appearance to her intelligence - and she feels a powerful, irresistible urge to find reasons to look down on others, so that she can feel better about herself by comparison. For this reason, she is obsessed with finding skeletons in other peoples' closets, and dragging out those skeletons for the world to see. She doesn't care what consequences her actions have in the lives of others, as long as she can feel superior to them.

Kashiko Murasaki is a mischief-maker and an instigator. She enjoys spreading gossip and rumors so that she can watch the outcome from afar, silently proud of herself for successfully manipulating the actions of others. Her gossip often causes permanent damage to the relationships of other people, but she doesn't care. She rationalizes her behavior by insisting that her actions are merely harmless pranks, and that any consequences are the fault of others who are not handling her pranks well enough.

Eleanor Nightingale is the psych-ops of The Hex, and Arthur's older twin sister. She sells Arcane Enhancements and Coda weaponry. Albrecht Entrati's experiments turned Eleanor into a Protoframe, a partial Warframe that still retains their humanity. Eleanor possesses Nyx traits. Originally a Britannic woman, Eleanor shared an idyllic childhood with Arthur, never fighting once. Eleanor would often braid Arthur's hair and use makeup on him. Eleanor and Arthur's grandmother, Callista Penrose Nightingale, came to live with them due to "Pelham's Syndrome", which caused her mental state to deteriorate over time, to the point where she would be "shrieking" for long periods of time, even for the duration of their school day. Their father would make mention of putting a pillow over her head, leading Eleanor to suspect that he actually did kill their grandmother when she suddenly stopped shrieking in the middle of the night. Prior to coming to Höllvania, Eleanor worked as a journalist. Despite her profession's habit of inflating stories for profit, she wanted to do some good with her work. After Arthur arrived in Höllvania and informed Eleanor of the events in the city, she felt a strong need to report on the Techrot infestation and inform the world of what had happened. She contacted a man named Danny MacIlvoy, obtained a forged visa and passport, and came into the city illegally. Due to the chaos within the city, she was able to slip in without incident. Eventually, she snuck into the subways, where she found an example of the Infestation - which she dubbed "Techrot" in her article on it. This would eventually replace the original name of the infection (Testudo Syndrome) and its scientific name (Technocyte Virus). Eventually, she became infected by the Techrot and sought a cure from Dr. Entrati. Before the events of 1999, the first volunteers that came forward to Dr. Entrati's offer to receive more than healing.

Nefarith is the leader of the Bonekrushers, a Landbreaker Clan that gained prominence by utilizing a strange gaseous material known as hazefyre. This substance, related to the Blight, temporarily enhances physical strength while inducing hallucinogenic and neurotoxic effects. The Endfield Intelligence Office has designated Nefarith as significant threat and predicts she will launch a major attack on the Civilization Band within the near future. She took control of the Bonekrushers and broke old clan rules to make them a powerful and terrifying force on Talos-II. Her main goal is to attack and destroy the civilized regions. Her clan uses a strange gas called hazefyre. It makes people stronger, but it also causes dangerous hallucinations. She can control the Blight, a dangerous decaying force in the world. She can manipulate the Aggeloi, which no one else in history has ever done.

Kokoro Momoiro was a victim of severe merciless bullying at her last school, and has resolved to never be a victim again. Upon arriving at Akademi, she immediately sought out the "bullies" of the school and desperately tried to get into their good graces for the purpose of making them see her as an ally, and not as a potential target. The firsthand knowledge of what it feels like to be bullied is still fresh in her mind, and she has absolutely no desire to abuse others, but she does it anyway...because she knows that she has to keep up the facade of being a bully in order to avoid being targeted by Musume and her friends. She has become what she hates, which has caused her to loathe herself deeply, but she would still rather hate herself than return to being harmed by others.

Hoshiko Mizudori is different from the other members of the bullies. She has no excuse for her behavior, such as receiving a poor upraising, having an inferiority complex, or being a former victim. She is simply a cruel person. The one and only thing that she cares about is her own personal gratification. Nothing else matters to her, especially not the thoughts and feelings of other people. She doesn't use any form of rationalization to convince herself that she is justified in harming others; the pure enjoyment she gets from doing so is reason enough.

The leader of the Bullies is named Mutsumi Rokuda. She is the daughter of a well-known loan shark, which has earned her the nickname "Musume Ronshaku," which translates to "Daughter Loanshark." Her rich father spoiled her rotten, and as a result, Musume grew up without any reason to treat others with kindness or respect. Gradually, she developed the belief that most people are "beneath" her, and that the "lowest" people are mere playthings for her to torment. Like a child who never learned the difference between right and wrong, she simply lacks the ability to see her victims as people who deserve empathy or compassion. She doesn't deliberately seek out victims, but when she spots one, she will happily seize the opportunity to treat another person like dirt.

Candice Catnipp is a Quincy and a member of the Wandenreich's Sternritter with the designation T: The Thunderbolt. Candice has a very short temper, as shown when she got annoyed at Bambietta for her habit of killing attractive male soldiers when irritated and then proceeded to get angry at Giselle for teasing her about her supposed tendency of having "fun" with her subordinates. She cares a great deal for her appearance, going as far as to get up hours before everyone else to do her hair, and cannot stand having it ruined in battle. Candice is also very shortsighted, reckless, and impatient; this volatile nature coupled with her horrible judgement of the situation causes her to make foolhardy decisions when engaging stronger opponents.

The vandal was none other than Ui's best friend. This was a massive shock to Ui, who had not detected even the slightest clue that her closest companion was connected to the vandalism. She also hadn't realized that one of the girls in her class was being bullied, or noticed that all of the victims of the vandalism actually did have something in common with one another. In retrospect, she felt that the vandal's identity should have been obvious to her from the beginning. This incident affected Ui dramatically. She couldn't help but wonder if she could have prevented the entire incident by simply being more observant. If only she had paid closer attention to her best friend, she would have realized what was going on, and would have intervened before the situation had a chance to escalate so drastically. She felt an overwhelming sense of guilt, almost as if the entire situation had been her fault. From that day onward, Ui swore to never allow a similar incident escape her notice. She became an extremely vigilant young woman, constantly on the lookout for potential warning signs that a hidden crisis was secretly underway. This earned her a reputation as a nosy girl who is utterly incapable of minding her own business - some students have even begun to refer to her by the mocking nickname of "Witness-chan."

Pippi Osu is part of Gaming Club at Akademi Academy. She is obsessed with rhythm games and gacha games, Pippi Osu is also best friend with Mai Wakahara with her anime ideas, and they make a perfect gaming duo. Pippi Osu spend money of gacha games to get more and more characters, calling her "whale". But even she can't resist of... some of characters, Pippi Osu won't resist to buy it or farming it, even Pippin Osu asked Mai Wakahara to make cosplay of specific characters.

Ichiko Saikou is the firstborn daughter of Saisho Saikou, the founder of Saikou Corp. She was first in line to inherit Saikou Corp from her father, although it would ultimately be her brother who inherited the company. As the daughter of one of the most intelligent and influential men of the 20th century, many people expected her to excel academically. However, throughout her teenage years, her performance at school was never above average. Because she failed to live up to the impossibly high expectations placed on her, she was treated unkindly by her peers, leading her to have many unpleasant experiences throughout high school. Ichiko Saikou vanished from the public eye in 1990. The disappearance of Ichiko Saikou is a mystery; nobody knows why she vanished or where she went. Some people theorize that she may have been unable to handle the immense expectations placed on her by her father and the world, so she fled Japan to live in secrecy overseas, where she enjoys a quiet and peaceful life. Other, more extreme theories postulate that her father executed her for failing to live up to his standards. To this day, nobody knows the ultimate fate of Ichiko Saikou or where on Earth she might be.

Nemesis is a character who attempts to hunt and eliminate you. Depending on what difficulty you have chosen, Nemesis might be invincible, and might also be disguised as one of the female students. She another assassin who wants to remove her competition? Or, true to her namesake - the Greek goddess of retribution - is she here to take revenge on you for the sins of her past? She is much more dangerous when she sees you.