The protagonist of the series, Yun starts off as a novice player of the popular Virtual Reality MMORPG Only Sense Online. His real identity is Shun, an Ordinary High-School Student with little interest in video games and who only started playing OSO at the behest of his best friend Takumi. Thanks to the game system mistaking his sex and an accidental mistyping on his part, his in-game persona is a long-haired beauty with a feminine-sounding handle "Yun".
Yun takes a casual approach towards playing OSO, which coupled with his inexperience in the game, causes him to pick up a wide range of unpopular Senses. His primary weapon is a longbow, which he manages to excel in using despite its poor reputation in-game.
- Archer Archetype: Yun's weapon of choice, the bow, as well as his all-rounded Sense build and his preference to play alone, makes him a good representative of this trope.
- Attractive Bent-Gender: Yun's avatar in OSO, while based off of his real body, is "enhanced" by the game system to appear even more feminine, resulting in a long-haired beauty.
- It should be noted that Yun's in-game avatar is not merely a feminine-looking boy, but it in fact genuinely female. This is proven at the hot springs: the system does not allow anyone to enter the side belonging to the opposite gender (for hopefully obvious reasons) and Yun is unable to enter the male side of the baths.
- An Axe to Grind: Kinda. He eventually gets an ax-like kitchen knife, Meat Cleaver - Heavy Black, for both cooking and strong but slower melee attacks.
- Big Brother Instinct: Yun is very caring to his younger sister Myu, although the latter tends to treat him as a Cool Big Sis instead in OSO, much to his chagrin.
- Blob Monster: Has Slimes that she keeps for use as distractions or to buy time or trip traps ahead of time.
- Born Lucky: Yun always has a knack of getting rare drops from mobs and bosses. Sei sometimes is annoyed that she never really gets drops she wants while her little brother oftentimes gets good drops instead.
- Bow and Sword, in Accord: Yun actually does not use swords; instead he has a kitchen knife which he uses as a secondary weapon when he is forced to engage in close quarters combat.
- He eventually does get a katana-like kitchen knife, Dismantling Knife - Blue Dancer, which can be wielded with one or both hands.
- Cassandra Truth: Despite his constant retorts that he is not a girl and his consistent usage of masculine speech, nobody in OSO other than his real life acquaintances believes him and instead assumes he is just roleplaying as an Ore Onna. This is not helped by the fact that his real-life acquaintances always tease him by intentionally never supporting Yun when he insists he's a guy.
- Childhood Friend: Has been friends with Taku since young.
- Combat Medic: Whenever Yun joins a party, he will provide ranged support with his bow and also help to provide additional healing with his large assortment of self-made potions if necessary.
- Cross Player: Is one unwillingly in OSO thanks to the system misidentification.
- Dishing Out Dirt: Yun eventually picks up the Earth Element Talent Sense as a supplement, partly because none of his acquaintances have it and partly because of the spells it offers suits his solo play style pretty well.
- Dude Looks Like a Lady: The reason why the OSO system misidentified him as a female in the first place.
- Embarrassing Nickname: Receives the nickname "Young Beasts' Nanny", or simply "Nanny", after the "Forest Camping Game" event in volume 2, which he finds very embarrassing.
- Friend to All Living Things: Has the uncanny ability to attract young beasts during the "Forest Camping Game" event, which gave rise to his nickname "Nanny" as mentioned above.
- In Touch with His Feminine Side: The reason why nobody believes he is a Cross Player in OSO. In fact, Sei and Mikadzuchi actually remarked that Yun has higher "girl power" than either of them!
- Item Caddy: He comes to almost any fight or event with an almost Crazy-Prepared supply of healing and mana-restoring items, ready to keep himself and anyone else alive. He even simulates the "Exclusive Items" side of the Caddy by keeping some of his toys solely for his own use, such as his spell-charged Magic Gems.
- Jack-of-All-Trades: Has one of the widest range of Senses shown in the entire series, including combat, crafting and survivalist Senses.
- Little Bit Beastly: Yun becomes a fox girl in volume 13 after merging together with Zakuro after he gained 3 tails.
- Magic Enhancement: Yun primary purpose in battle is supporting others by using Enhancement Magic. He also uses it to increase his speed and strength while crafting or farming in order to get around strength requirements and get through it faster.
- Mistaken for Romance: Because of his appearance as a girl, other OSO players have a tendency to assume he has a Childhood Friend Romance with Taku, much to his chagrin.
- Mistaken for Subculture: Because of his constant usage of masculine speech, people frequently assume Yun is an Ore Onna in OSO.
- Nice Guy: Yun has a very kind and caring personality almost to the level of an Extreme Doormat. This almost becomes a problem for him in OSO when he frequently underestimates the values of the items he makes, until his crafting acquaintances advise him on their proper prices. Even then, he still limits the quantities of items he is selling, so as not to destabilize the in-game market.
- Only One Name: His last name is never revealed.
- Player Headquarters: Yun's shop in OSO, aptly named the Atelier, serves as one for him.
- Raven Hair, Ivory Skin: Yun's long black hair contrasts very well with his pale skin, and in OSO where fantastic hair colors are the norm, this contrast accentuates his already substantial beauty.
- Selective Obliviousness: Played for Laughs whenever he pretends not to notice the compliments or lecherous remarks (or even both) other OSO players enamored by "her" beauty say.
- Supreme Chef: Yun is a very good cook in the real world, and is more or less the family cook. This inspires him to take up the erstwhile unpopular Cooking Sense after the satiety mechanic is introduced in OSO, and he finds out that he can actually use the game to practice his actual cooking skills.
- Team Chef: Acts as one for his party during the "Forest Camping Game" event.
- Why Did It Have to Be Snakes?: Yun is especially afraid of horror-type undead mobs (ghosts and the like), although he does not seem to be bothered by non-anthropomorphic undead mobs like will-o'-the-wisps.
- Zettai Ryouiki: Invoked by Cloude, when he purposely designed Yun's winter clothing set such that the white outer coat reaches his thighs at the back but tapers off in front which barely covers his hot pants, creating the illusion of a miniskirt. Then the set is completed with a pair of knee-high socks, creating this trope.
One of the top crafters in OSO, Magi is also the first friend Yun made in-game, after the latter patronized her market stall and sold her a number of good quality healing potions. Intrigued by Yun's unconventional Sense build, she quickly became fast friends with him, and acts as a mentor figure for him in the game, although she still believes Yun is a girl, despite his protestations otherwise.
Magi specializes in smithing metal equipment in OSO, and after the events in volume 3, establishes the Crafting Guild together with fellow crafters Cloude and Lyly and becomes its guild master.
- An Axe to Grind: Although Magi usually avoids combat, she is fairly proficient in the use of axes, including throwing them, if the need to fight arises.
- Big Sister Mentor: Acts as one to Yun.
- The Blacksmith: Magi is one of the top smiths in OSO, and is already renowned in-game since its beta version.
- Drop the Hammer: Is able to use hammers to fight.
- Pervert Revenge Mode: Often threatens Cloude with her fists whenever the latter tries to do something perverted.
- Playing with Fire: Has the Fire Element Talent Sense as a supplement.
- Stupid Sexy Flanders: Magi has a brief moment of attraction towards Yun during their first meeting, which she thinks is this trope because she assumes Yun is a girl.
- Team Mom: Acts as one for her crafting acquaintances, and later the Crafting Guild as well in her capacity as the guild master. It is stated that her fellow crafters elected her as guild master precisely because her caring and amiable personality makes her a good public face for the guild.
One of the top crafters in OSO, Cloude specializes in crafting cloth and leather armors and also branches out to making cosplay costumes. He is a bit of a pervert and has a habit of asking female players to model his creations for him, including Yun, much to the annoyance of the latter.
Cloude is one of the founding members of the Crafting Guild alongside Magi and Lyly and serves as its sub-master.
- Casting a Shadow: Utilizes Darkness magic if he needs to engage in combat.
- Dungeon Maintenance: Receives the right to make a dungeon for three months as a reward from the "Forest Camping Game" event, and he spends a lot of time in planning the dungeon to maximize returns from it, which turns out to be much harder than he thought.
- Instant Cosplay Surprise: He would like to do this to pretty female players in OSO if given the chance. So far though only Yun and Lyly has been shown to be subjected to that treatment, and neither of them are girlsnote .
- Smart People Wear Glasses: Cloude is one of the few players shown wearing glasses in OSO, and he has a flair for strategy, such that he serves as the brains for the Crafting Guild.
- The Strategist: Cloude has a flair for planning and organizing, which also extends to large-scale raids in OSO, and he was actually invited to act as the strategist by other players to clear the raid segment during the "Forest Camping Game" event.
One of the top crafters in OSO, Lyly specializes in woodworking, which thanks to the unpopularity of bows in-game means that most of his orders are wands and staves. He appears to be the youngest among the crafting trio.
Lyly is one of the founding members of the Crafting Guild alongside Magi and Cloude.
- An Axe to Grind: He is stated to have the Axe Sense in his character profile, although he is never actually shown fighting with axes in the novel proper. Instead, he uses them to chop trees.
- Cheerful Child: Lyly has a very cheerful personality, and appears to be a pre-pubescent boy.
- Knife Nut: His primary weapon is a pair of daggers.
- Verbal Tic: Has a habit of suffixing every name with "-cchi".
- In Japanese terms, this equates to calling everyone by a cute, feminine nickname.
- Wholesome Crossdresser: Passes off very well the few occasions Cloude requested him to model his costumes.
Yun's younger sister, Myu is a hardcore gamer and was a beta tester for OSO. She is very thrilled when she learned that her older brother is joining OSO, and helped him out in the registration process. Her Min-Maxing approach to playing OSO as opposed to Yun's casual playstyle means that the two of them actually tend not to play together, although she does frequent Yun's shop for his high-quality consumables. Instead, Myu usually plays OSO together with a party of five other girls of similar age and is its nominal leader.
Myu's real name is Miu.
- Cute Bruiser: She is very cute, and also one of the strongest players in OSO.
- Gamer Chick: Enjoys playing a wide range of video games, including OSO.
- Genki Girl: Has a very energetic personality, which she carries over into OSO as well.
- Hero of Another Story: Myu's path to prominence within OSO is definitely an interesting story of its own right, and she does, in fact, receives a spin-off side story centered around her point of view. Amusingly, her conventional combat-oriented play style means that she fits The Hero trope much better than her older brother Yun.
- Heroines Prefer Swords: Myu's weapon of choice in OSO is a one-handed sword, which fits into The Paladin persona she is cultivating.
- In Harm's Way: Has a penchant for putting herself through incredibly difficult challenges in OSO, such as trying to take on a boss monster in solo combat. This helps to refine her combat skills much more quickly than conventional Level Grinding, with the added bonus of faster leveling of her Senses. Since such challenges are usually conducted at night, in the event that she got killed in-game, she would just simply log out for the day and let the death penalty naturally expires over the night.
- Jeanne d'Archétype: Myu tries to invoke this with her Magic Knight Sense build. Her weapon and armor even bear the name of Jeanne d'Arc!
- Light 'em Up: Utilizes Light magic as part of her Magic Knight Sense build.
- The Paladin: Myu invokes this with her sword-and-light magic Sense build.
- Red Baron: She is known in OSO by her nickname "Silver Paladin".
- She-Fu: Myu revels in three-dimensional acrobatic combat, made possible by her Action Restriction Release Sense.
- You Gotta Have Blue Hair: Myu's Digital Avatar in OSO has white hair.
One of Myu's party members, Lucato serves as the party's tank and is, in fact, the one that takes the actual role of commanding the party in combat. Her calm and down-to-earth personality serve as a Foil for Myu, although both of them are in very good terms with each other.
- Affectionate Nickname: Myu addresses her as "Luka-chan".
- BFS: Alternates between using a bastard sword (massive for her size) and a smaller longsword (with an optional shield) in OSO, depending on the conditions in the field.
- Gamer Chick: Downplayed. OSO is, in fact, Lucato's first MMORPG, and she only joined the game because she wants to try being a hero.
- Heroines Prefer Swords: Lucato's desire to be The Hero is reflected in her weapon of choice, the sword.
- Knight in Shining Armor: Is enamored by this type of characters in Heroic Fantasy stories, and tries to emulate them in OSO.
- The Strategist: Serves as this for her party during combat.
- Supporting Leader: Although Myu is the nominal leader of her party, it is Lucato who takes up the role of commander during actual combat due to her superior planning and organizing skills.
One of Myu's party members, Toutobi serves as the party's scout and is adept at disarming traps. In combat, her assassin-style Sense build enables her to dish out high damage stealth attacks, allowing her to be able to survive solo encounters like Myu if needed.
- Affectionate Nickname: Myu addresses her as "Tobi-chan".
- Back Stab: Is very capable of dealing such attacks thanks to her Sense build.
- Badass Adorable: Very cute and very powerful.
- Combat Pragmatist: Makes full use of her capacity for evasion and stealth attacks during the PvP Tournament in volume 5 and deals hit-and-run attacks while inducing opposing players to deal collateral damage against each other.
- Critical Hit Class: Her Sense build is designed to evoke this.
- Knife Nut: Toutobi's weapon of choice is a pair of daggers.
- The Quiet One: Is the quietest in her party and generally does not speak much.
- Stealth Expert: Her Sense build allows her to move around without being discovered.
One of Myu's party members, Hino serves as the party's vanguard fighter and specializes in long melee weapons. She is an avid gamer who have known Myu since the beta version of OSO and both of them have a similar personality. She has been described as the party's "mood maker".
- Blade on a Stick: One of her weapons of choice is the spear.
- Close-Range Combatant: Her only way to deal ranged attacks is to throw her weapon.
- Cute Bruiser: As a vanguard fighter specializing in melee combat, she would definitely appear as such.
- Drop the Hammer: Her other weapon of choice is the hammer, which she seems to use more often than the spear.
- Gamer Chick: Is an avid video gamer just like Myu.
- Genki Girl: She is very cheerful and energetic.
One of Myu's party members, Kohaku serves as a rearguard support mage for her party. She specializes in Wind magic and has a balanced Sense build overall. Her no-nonsense demeanor makes her the Straight Man in the party as she handily dishes out timely retorts against any wacky utterances.
- Blow You Away: Specializes in Wind magic, which she often utilizes in tandem with Rirei's Fire magic for a synergistic effect.
- Kansai Regional Accent: Speaks in a Kansai dialect.
- Making a Splash: Is stated in her character profile that she has knowledge in Water magic as well.
- Meganekko: One of the few players shown to wear glasses in OSO.
- Miko: Her worn equipment in-game resembles a miko uniform.
- Straight Man: Issues quick retorts whenever someone in her party says something stupid or perverted (usually Rirei for the latter).
One of Myu's party members, Rirei serves as a rearguard mage for her party. She specializes in Fire magic, and unlike Kohaku, she has a much more offensive Sense build. She is known in her party for her (often) wild delusions and is especially excited when Myu and Yun get close to each other, much to the latter's embarrassment.
- Black Mage: Her Sense build emphasizes on pure offensive power.
- The Gadfly: Enjoys teasing her acquaintances.
- Playing with Fire: Specializes in Fire magic, which she often utilizes in tandem with Kohaku's Wind magic for a synergistic effect.
- Robe and Wizard Hat: Her worn equipment is comprised of these.
- Yuri Fan: Rirei is a fan of the Yuri Genre, and thinks Myu and Yun getting together is hotnote .
Yun's best friend in the real world, Taku is a hardcore gamer and was the person who introduced OSO to Yun. Like Myu, he was a beta tester for OSO and is currently one of the top players in-game. Taku is heavily dependent on Yun for schoolwork, although he becomes inordinately helpful to Yun while in OSO. He generally parties together with a group of four other male and female players.
Taku's real name is Takumi.
- Childhood Friend: Has been friends with Yun since young.
- Combat Pragmatist: He has no qualms in wearing down his opponents in the PvP Tournament by luring them into areas where other competitors are fighting each other so as to make them deal collateral damage against all of them.
- Dual Wielding: Wields two swords in combat.
- Hero of Another Story: He is a skilled player whose online gameplay videos are famous enough to inspire new players in OSO; however due to the nature of this series, his exploits will only be described peripherally.
- Heroes Prefer Swords: Is implied that he is trying to invoke this trope by choosing the sword as his primary weapon.
- Mistaken for Romance: OSO players who do not know Taku in real life have a tendency to assume he is in a Childhood Friend Romance with Yun. He makes no attempts to disabuse them of that notion.
One of Taku's party members, Kei serves as the party's tank. He has a gruff appearance but is actually a nice guy.
- The Big Guy: He is not only the party's tank but also its most burly member as well.
- Gentle Giant: Actually very kind and thoughtful despite his surly appearance and habit of speaking bluntly.
- Luckily, My Shield Will Protect Me: Sometimes uses a shield.
- Stone Wall: As the party's tank, his job is to keep their enemies focused on him.
One of Taku's party members, Gantz serves as the party's vanguard fighter. He has an energetic personality and can be reckless in combat.
- Bare-Fisted Monk: Gantz specializes in barehanded combat in OSO.
- Boisterous Bruiser: Although he is smaller in size than Kei, his loud and energetic personality, together with his specialty in close quarters combat, qualifies him as such.
- Does Not Know His Own Strength: In one occasion, he accidentally killed Mami's pet Gel just by poking it due to his martial arts Senses.
One of Taku's party members, Minute serves as the party's healer. She is a bit of a tease.
- Carry a Big Stick: Uses a mace.
- The Gadfly: Likes to tease Yun about "her" relationship with Takunote . She also once plotted an elaborate prank against the male members of her party with the assistance of Yun and Mami, although only Gantz fell for it in the end.
- White Magician Girl: Her worn equipment and her role as the party's healer evokes this trope.
One of Taku's party members, Mami serves as the party's rearguard mage. She is a very reserved person.
- Blow You Away: Can use wind magic.
- Cute Witch: Appears as such with her worn equipment and her specialty in offensive magic.
- Meganekko: One of the few players shown to wear glasses in OSO.
- Shrinking Violet: She is shy enough that she had to rely on Minute to make a request on her behalf to Yun regarding the possibility of synthesizing a pet in OSO.
Yun's older sister, Sei is an avid gamer and a former beta tester of OSO just like her younger sister Myu. She is one of the top players in OSO and serves as the sub-master for the guild 【Eight Million Gods】. Although she is usually calm and composed, she can get upset when the so-called "Greed Sensor" strikes and she's unable to get the rare drops she wants.
Sei's real name is Shizuka and is currently a university student studying away from home.
- Beauty Mark: Has one under her left eye.
- Boring, but Practical: Although her high level means that she has access to a vast array of powerful spells, her favored tactic is still to set up a barrage of Aqua Bullets. Although it is just a basic Water attack spell, its fast casting speed and low cooldown time makes it more flexible to use than many of her more flashy spells.
- Born Unlucky: She suffers a lot from "greed sensor".
- Gamer Chick: She is an avid video gamer.
- Hero of Another Story: Her rise to prominence in OSO is good enough to be a story itself.
- Instant Fan Club: Gathers one during her participation in the PvP Tournament. It was quickly dispersed by another horde of jealous guys.
- Lady of War: Freezes her enemies with style and elegance.
- Magic Staff: One reason why Sei is such a formidable player is because she is fully capable of defending herself in melee combat with her staff if her opponents manage to survive her barrage of Water magic and close onto her.
- Making a Splash/An Ice Person: Sei specializes in Water magic, and also Ice magic after she raised her Water Element Talent Sense to a certain level.
- Onee-sama: She serves as one to both Yun and Myu, and is the most ladylike character shown in this series.
- Red Baron: She is known in OSO by her nickname "Still Water's Witch".
- Squishy Wizard: Subverted. While her defense is still low compared to melee-oriented players, she is not helpless at all when forced into close quarters combat.
- You Gotta Have Blue Hair: Sei's Digital Avatar has light blue hair.
The guild master of 【Eight Million Gods】, the largest guild in OSO, Mikadzuchi is also unsurprisingly one of its top players. She specializes in stick-fighting and enjoys a good fight.
- Bifauxnen: Has an androgynous appearance, which undoubtedly helped to enhance her charisma.
- Cool Big Sis: She commands the respect and admiration of many players, who see her as such.
- Hard-Drinking Party Girl: Enjoys drinking in excess in her downtime in-game. She even dragged Yun down into a dungeon on one occasion to hunt for a Rare Random Drop in the form of a canned food as an accompaniment for the alcohol!
- Simple Staff: Her weapon of choice is an unassuming long stick.
- You Gotta Have Blue Hair: Mikadzuchi has wine-red hair in OSO.
One of the crafters in 【Eight Million Gods】, Otonashi specializes in crafting accessories. He usually hangs out with his fellow crafter Langley.
- Hand-Hiding Sleeves: Wears a kimono with oversized sleeves that cover his hands.
One of the crafters in 【Eight Million Gods】, Langley specializes in crafting accessories. He usually hangs out with his fellow crafter Otonashi.
- Walking Shirtless Scene: Wears a jacket that leaves much of his upper body naked.
FleinThe guild master of the 【Flame Prison Corps】 PK Guild.
- Blood Knight: PKs for the challenge of it, rather than greed or trolling.
- Noble Demon: When the Ghost Wolf raid takes part, he intentionally stands aside, justifying his actions as a statement that it's neither fun, profitable nor sporting to just kill a bunch of lower-level players. He also announced himself before his time in the PvP arena.
- One-Hit Kill: Knows the PK skill <<Killing Edge>>.
- Thanatos Gambit: When he knew he was likely to get wiped out in the forest outside the Crafting Guild event, he used a skill to deplete his own HP so that he wouldn't take the much more substantial penalty.
TobiasThe sub-master of the 【Flame Prison Corps】 PK Guild.
An OSO player, Letia likes to roam around the game world with her menagerie of pet beasts. She first encountered Yun during the "Forest Camping Game" event in volume 2 after she passed out due to hunger and the latter offered her food. Since then, she crosses paths with Yun from time to time.
Helps Yun to mentor two beginner players Lyna and Al and eventually forms a guild, Fresh Green Wind, with them and serves as the guild master in volume 5.
- The Beastmaster: Relies on her large collection of tamed pets for combat support.
- Big Eater: She enjoys eating a lot in-game, and her pets are big eaters too.
- Nature Hero: She tries to roleplay as one with her elf-like appearance and her beast taming-oriented Sense build.
- Pointy Ears: Her Digital Avatar sports a pair to make her look like an elf.
A new player to OSO when the second batch of VR Gear came out. She and her twin brother were helped by Yun and Emily when they first start. She and her brother later joined the Fresh Green Wind.
Her real name is Nana.
- Blade on a Stick: She uses spears. She first had a long spear before switching to a short spear.
- Luckily, My Shield Will Protect Me: She also uses a shield.
- Red Oni, Blue Oni: The Red to Alphard's Blue. She is impatient and prone to rushing headfirst without a plan.
- Shield Bash: She can use her shield as a substitute weapon in areas too narrow for her to wield her spear effectively.
A new player to OSO when the second batch of VR Gear came out. He and his twin sister were helped by Yun and Emily when they first start. He and his sister later joined the Fresh Green Wind.
A mysterious OSO player known as the "Material Merchant", Emily is, in fact, Yun and Taku's classmate in the real world. She is a solo player like Yun and takes great lengths to keep her identity secret, going as far as disguising her in-game handle as "Emilio" and hiding her appearance with a mask. She specializes in synthesizing unique crafting materials and fights with the aid of her hand-crafted golems.
Emily's real name is Emiri Endou, making her the only character as of volume 6 that is depicted with a full name.
- Class Representative: She is one for her class.
- Closet Geek: She hides her interest in video games in school as she thinks it will spoil her image as a responsible class representative.
- Cool Mask: Habitually wears a mask that covers half of her face in-game.
- Gamer Chick: Is very well-versed in many video games.
- Mook Maker: One of her specialties is her ability to craft wooden dolls and golems and use them in combat.
- Only Known by Their Nickname: Most players who interact with her addresses her by her nickname "Material Merchant" only.
- Whip Sword: Wields one as her weapon of choice.
A hobbyist player Yun and Taku met and helped them train in the 【Climbing】 sense.