This is the character page for the light novel and anime series Beyond the Boundary. Be wary of unmarked spoilers ahead!
A young man who loves girls with glasses, is half-Yomu, and is thus immortal. His mother is a busy Spirit World Warrior, and is often away from home. He meets Mirai when simply walking outside of their school and seeing her standing on the edge of the roof. Unaware of her powers, he mistakenly assumes that she's about to commit suicide. Their relationship begins with Mirai constantly attacking him as practice, but blossoms into a close friendship after he accompanies her on ventures to kill violent Yomu.
- Anguished Declaration of Love: Towards Mirai. Twice. Once when he meets Mirai again on the roof, unaware that she's lost her memories, and another when he snaps her out of her youmu parasite induced rampage in the movie.
- Arbitrarily Large Bank Account: Akihito apparently has enough of a fortune to buy entire crates full of glasses, is subscribed to various glasses catalogues, and continues to buy new glasses for Mirai everyday (which she still refuses to try on). And according to Ayaka, he also pays "good money" for photos of cute girls wearing glasses. Exactly where all of Akihito's money comes from is a mystery.
- Battle Couple: With Mirai in episode 12, as they're fighting against the core of Beyond the Boundary and all the hostile youmu it's absorbed.
- Belated Love Epiphany: Akihito realizes he's in love with Mirai after Mirai had already sacrificed herself to the Beyond the Boundary and wiped herself from existence in order to save him.
- Big Damn Heroes: Saves Mirai from being cut in half by Sakura.
- Black Eyes of Crazy: Combined with Red Eyes, Take Warning when possessed by his youmu side.
- Brought Down to Normal: When he had the Beyond the Boundary removed for 3 months, he lacked his immortality and was able to control his youmu side. Snapped back after he returns the Beyond the Boundary to being inside him.
- Butt-Monkey: Mirai uses him as a practice dummy, Mitsuki labels him a pervert and teases him, Hiroomi gives him weird nicknames...this guy doesn't get much respect.
- Childhood Friends: With Mitsuki and Hiroomi. Although it's implied that Hiroomi and Mitsuki are less "friends" and more "guardians" to make sure The Kyoukai No Kanata doesn't go berserk.
- Chivalrous Pervert: He's pervert with a huge glasses fetish, but he really cares about Mirai.
- Cooldown Hug: Is the recipient of one from Mirai when Beyond the Boundary goes berserk during the events of the Hollow Shadow arc. He also gives one to Mirai in the movie (also confessing his love for her in the process ) when she's Brainwashed and Crazy by Miroku's parasite youmu.
- Dark and Troubled Past: Implied. The second episode shows Akihito standing over a body, staring in horror at his bloody hands. Episodes 4 and 5 reveal he actually did almost kill Hiroomi. There's also the events shown partially from his childhood about being ostracized because of his immortality.
- Deadpan Snarker: Even when he's dripping with his own blood.
- Demonic Possession: Is briefly possessed by the Hollow Shadow.
- Dogged Nice Guy: He continually goes out of his way to help Mirai and attempts to befriend her despite her repeated refusal to get involved with him.
- The Dulcinea Effect: When he first sees Mirai, he thinks she's going to commit suicide and immediately runs to try and stop her.
- Embarrassing Nickname: He is called "Akkey" by Hiroomi. He says it fondly, but Akihito finds it embarrassing.
- Good Thing You Can Heal:
- Gets stabbed no less than 6 times by Mirai, at least once through the chest. While it doesn't kill the guy, Akihito acknowledges that it hurts like hell.
- He also gets stabbed through the chest by the Hollow Shadow when it possesses him. Afterwards, Mirai is forced to stab him multiple times in a violent attempt to exorcise the Hollow Shadow.
- Based on peripheral comments, he has a bit of a tendency to meddle and try to help people because his immortality means he's in little danger.
- In Episode 0 Hiroomi gets him through the chest once, he takes 3 more to protect Hiroomi and then Miroku pretty much makes mincemeat out of him. Not to mention the Cursed Blood Mitsuki uses on him.
- In the movie, I'll Be Here, he gets his left foot severed by brainwashed Izumi while trying to protect Mirai. Later on, he loses his entire left arm to Mirai herself, also brainwashed and under the influence of Miroku's parasite youmu. Thankfully, he's able to reattach/regenerate the limbs in both cases.
- Half-Human Hybrid: His mom is a human Spirit Warrior and his dad is a youmu.
- Has a Type: He's into Bespectacled Cuties. Naturally, he develops a crush on the bespectacled Mirai.
- Healing Factor: Akihito describes himself as immortal; he can heal from any wound. He can still feel pain, though.
- Heroic BSoD: He apparently had one right after he almost killed Hiroomi.
- Episode 0 supports this.
- I Am Who?: He knows he's an immortal half-youmu, what he doesn't know is he possess the Beyond the Boundary, the strongest youmu inside him.
- I Cannot Self-Terminate: States in Episode 0 that death is the best option for him, and later tries to convince Hiromi to kill him when his when his ability to control his Spirit Warrior powers improves.
- Immortality Hurts: Despite his regeneration, he frequently complains that his injuries still hurt.
- I Want My Beloved to Be Happy: After Mirai comes back with no memory of him or her powers in I'll Be Here, Akihito decides to forego making her remember in order to let her live a happier life.
- Lovable Sex Maniac: He proudly proclaims his glasses fetish to the world and apparently pays good money for pictures of bespectacled hotties in Fanservice-y costumes.
- Love at First Punch: Mirai stabs him through the chest in their first meeting. He develops a crush on her soon afterwards.
- Minor Living Alone: His mother is always traveling, so Akihito pretty much lives on his own.
- My God, What Have I Done?: After Mirai snaps him out of youmu mode in Episode 4. He merely Face Palms when he sees Hiromi, Nino and Ayaka sprawled around him, but then sees Mirai's head injury, realizes he's to blame and is furious.
- Non-Action Guy: Despite hanging out with Spirit World Warriors, he doesn't have any combat skills. Until he gets an 11th-Hour Superpower in Episode 12 and can partially control his youmu side at least.
- Oblivious to Love: In Episode 10, he misses the hints Sakura gives him about the obvious reason Mirai is taking care of him. Though given the fact that day was actually All Just a Dream that Mirai created before she absorbed Beyond the Boundary, it may have been intentional that she made it so that Akihito wouldn't realize things were out of place. Once Akihito realizes what's going on, he actually has a Love Epiphany in the same episode and says that a life without Mirai isn't worth living.
- Official Couple: With Mirai.
- Official Couple Ordeal Syndrome: The events of the sequel movie focus on Akihito dealing with Mirai coming back to life but at the cost of her memories. He spends about half the movie trying to avoid her, pained at her having forgotten about him but insisting that he wants Mirai to live a normal life. Things take a turn for the worse when Mirai starts to regain her memories, but is also possessed by a youmu that feeds on human hatred and despair. The climax of the film is literally Akihito saving Mirai by confessing his love for her and promising that no matter what happens, he'll protect her.
- Ordinary High-School Student: Just a normal high school student who also happens to be an immortal half-youmu and ends up as the practice dummy of a girl with a sword made of blood. It's later revealed he is actually the host for an immensely powerful Youmu known as Beyond the Boundary or Kyokai no Kanata.
- Person of Mass Destruction: When his youmu side is in control, he's strong enough that it takes 3 people to contain him, and even that wasn't enough in episode 4. One stray ball of fire caused a humongous explosion several kilometers away and he created a gigantic crater around the site of his containment.
- Playing with Fire: Appears to be his main method of attack when possessed by his youmu side.
- Power Dyes Your Hair: His bangs turn green when his youmu side goes out of control.
- Strange Minds Think Alike: He and Hiroomi. Hiroomi's quirks aside, they are very, very much alike. They generally act like they practice their interactions with each other. Nino-san actually calls them out on it in episode 7.
- Superpowered Evil Side: After another youmu possesses him, his youmu side goes out of control, turning him into a fireball-spewing rage monster. This apparently happens regularly, and his handlers may have to kill him if they can't contain his crazy-mode.
- Took a Level in Badass: Episode 12, as he has part of the Kyoukai no Kanata in his hand he has access to some of it powers. He later reseals the Youmu inside of him again.
- Wacky Parent, Serious Child: The Serious Child to Yayoi's Wacky Parent. He's quite normal and levelheaded, leaving his glasses fetish aside, in contrast to his mother who is an eccentric Cosplay Otaku Girl who is always embarrassing him.
A young girl who is descended from a clan of Spirit World Warriors who are capable of manipulating their blood and turning it into weapons. Since this power was highly feared and envied, her clan was wiped out, and she was eventually the only remaining member. At first she constantly attacks Akihito because of his immortality, thus making him a good means of training, but becomes close friends with him after he agrees to help her fight normal Yomu.
- A-Cup Angst: Not brought up much, but it's clear that Mirai is somewhat sensitive about her small bust.
- Accidental Murder: She accidentally killed her friend Yui Inami when the latter was possessed by the Hollow Shadow.
- Action Girl: For an inexperienced Spirit Warrior, Mirai can kick ass like no one's business.
- Action Girlfriend: Before meeting her, Akihito tried to simply live as a normal high school student and didn't get much involved with the Spirit World despite being the son of a Spirit World Warrior and a half-youmu. Once Mirai becomes his friend, he accompanies her on ventures to kill violent youmu.
- All of the Other Reindeer: Due to the blood powers of her clan, Mirai is treated as an outcast by other Spirit Warriors. Even when she was adopted by the Inami family, she was kept isolated because of her powers and Yui was her Only Friend.
- Almost Kiss: In Akihito's dream. Whether she was too overwhelmed or simply couldn't stand on tiptoe for that long, either way, she disappears before anything further can happen as Akihito wakes from his coma.
- Badass Adorable: Cute as a button and fully capable of beating seven shades of shit out of you.
- Bad Liar: She'll usually start cleaning her glasses and stammering whenever she's being dishonest. Even if she's not wearing them, she'll go through the cleaning motions.
- Battle Couple: With Akihito in episode 12, as they're fighting against the core of Beyond the Boundary and all the hostile youmu it's absorbed.
- Because You Were Nice to Me: The reason for her attachment to Yui, and later to Akihito.
- Becoming the Mask: She originally became friends with Akihito because the Nase clan had hired her to kill him, but she wound up falling in love with him for real and couldn't bring herself to do so.
- Bespectacled Cutie: She initially appears clumsy, awkward, and tries not to associate herself with others, but is actually a kindhearted and sweet (not to mention a badass) girl with glasses.
- Big Eater: Seems to be, judging by the large number of plates she cleaned when eating at a Mexican restaurant with Akihito. She may need to eat a lot in order to restore lost blood.
- Bloody Murder: She utilizes her blood in combat. She generally freezes it into a sword, but can also shoot droplets as projectiles and form a shield. Her blood becomes corrosive after removing her ring.
- Brainwashed and Crazy: In the movie, after Miroku infects her with a parasitic youmu that feeds off hatred and despair and haunts its victims with visions of their darkest moment.
- Cast from Hit Points: Her powers use her blood, so overusing them gives her anemia.
- Catchphrase: "How unpleasant/You're unpleasant".
- Character Tic: Turning her back on the camera and tapping on her phone, apparently blogging while asking rhetorical questions. It's usually only used as a gag though.
- Clingy Jealous Girl: In episode 7, while visiting Akihito at his apartment to return something he forgot to take home, she notices a girl's pair of shoes by his door. She immediately gets upset and starts questioning him on who's visiting him, and at one point wonders if it's Hiroomi.
- Cooldown Hug: Glomps Akihito, stopping his fiery rampage and allowing him to regain consciousness. In the movie, she's the recipient of one, with Akihito hugging her and confessing his love for her after Mirai is possessed by Miroku's parasite youmu.
- Crouching Moron, Hidden Badass: In the initial episodes, Mirai is presented as too clumsy and inept to really be considered a threat. However, after she gets over her angst over killing Yui Inami, she suddenly starts kicking all sorts of ass.
- Cursed with Awesome: She's cursed with powerful blood powers that allow her to use her own blood as a sword, a shield and acid.
- Cute Clumsy Girl: Particularly in the first few episodes, she had a habit of tripping over frequently.
- Dark and Troubled Past: When she was a child, Mirai was adopted by the Inami family. She was kept isolated in the attic, but was befriended by Yui, a member of the Inami family. Mirai and Yui were close friends until the day that the Hollow Shadow swept into town. Mirai and Yui were caught in its wake, leading to Yui getting possessed. Mirai accidentally killed Yui while trying to fight off the Hollow Shadow.
- Demonic Possession: In the movie, Fujima Miroku infects her with a youmu that feeds off human despair and hatred, and for the second half of the film Mirai is Brainwashed and Crazy and is trying to kill her friends.
- Deuteragonist: The story is just as much hers as it is Akihito's.
- Fantastic Racism: She initially has no qualms stabbing Akihito as she claims because he's a youmu, he can deal with it. She noticeably gets better. It was really all part of her trying to figure out how to kill him, as per Izumi's plan.
- Glasses Are Sexy: Her glasses are one of the foremost things Akihito finds attractive about her, due to his glasses fetish. Humorously, Mirai finds this "unpleasant".
- The Glasses Come Off: Takes off her glasses before her final strike against Beyond the Boundary/Akihito in Episode 9. It's all the more meaningful considering it's an attempt to stop her love for him from blinding her (as it forces her to keep seeing his face throughout the fight) and it's the thing he loves that drew him to Mirai in the first place.
- Heroic Self-Deprecation: Believes that she doesn't deserve to be happy or have friends. Akihito tries to convince her otherwise.
- In Love with the Mark: She ends up falling for Akihito, who she was meant to kill.
- Kill the Ones You Love: She accidentally kills Yui, who was possessed by the Hollow Shadow, and later on she is forced to kill Akihito, as it is quite possible his Superpowered Evil Side would become dominant if he remained in that state once the Calm leaves, and that would be a very bad thing.
- Laser-Guided Amnesia: The last movie kicks off with her afflicted with this. Akihito is unwilling to reawaken her memories because of how much she'd suffered in the past and how she finally has a chance at living a normal life.
- Last of Her Kind: She is the last of her clan, who were wiped out by other Spirit Warriors out of fear.
- Minor Living Alone: Since she has no relatives, she lives in an apartment all by herself.
- Mistaken for Suicidal: The series starts with Akihito spotting Mirai standing on a roof. Thinking she's about to kill herself, Akihito runs to stop her only to find out she was luring him in to stab him because she sensed his youmu blood.
- Mundane Utility: Her blood can be used as a sword, as a corrosive substance to finish off youmu...and to pick locks.
- Nice Girl: She's very kind and sweet-hearted, underneath her withdrawn, brooding and very shy personality.
- Official Couple: With Akihito.
- Official Couple Ordeal Syndrome: The main plot of the movie, what with Mirai coming back to life but at the cost of losing her memories. Akihito tries to push her away because he wants her to live a normal, happy life even if it means she can't be with him. Things take a turn for the worse when Mirai starts to regain her memories, but is also possessed by a youmu that feeds on human hatred and despair. The climax of the film is literally Akihito saving Mirai by confessing his love for her and promising that no matter what happens, he'll protect her.
- Overdrawn at the Blood Bank: Rule of Cool applies, but she still frequently uses several times the amount of blood a human body contains within a single fight. Deconstructed after Episode 10; she used so much blood attacking the Beyond the Boundary that she doesn't exist anymore.
- Perpetual Poverty: Always seems to be struggling for money, to the point that she seems to barely be able to cover rent, and often seems to go hungry. Episode 6 reveals that a big part of that is due to her obsession with buying and maintaining bonsai trees.
- Pinocchio Nose: Tends to polish her glasses fervently when lying.
- Pint-Sized Powerhouse: She's short, but is shown to be quite powerful.
- Power Dyes Your Hair: In the movie, her hair turns jet black during her parasite youmu possession.
- Power Limiter: Wears a golden ring that suppresses her blood powers.
- Proper Tights with a Skirt: She wears black tights with her school uniform, which helps emphasise her modest nature.
- Rose-Haired Sweetie: Played With. She has pink hair, but she is introverted, awkward around people and carrying some heavy-duty emotional baggage; that said, though she is far more brooding than the usual stereotype, she's still a genuinely kind and sweet individual.
- Scary Shiny Glasses: Coupled with a brief Heroic BSoD when the others reveal in Episode 4 how they might have to deal with youmu Akihito.
- She Is All Grown Up: Though still on the short side, Mirai is noticeably taller and has a more slender, feminine physique in the movie. Justified since the events of the movie take place one year later.
- Specs of Awesome: She wears glasses and fights using cool blood manipulation powers.
- Star-Crossed Lovers: The purpose for her clan's existence is to destroy the Beyond the Boundary. She's fated to kill Akihito.
- Supernatural Gold Eyes: When she's under the influence of Miroku's parasite youmu.
- Tender Tears: When she was lost, and again after she calms down Youmu-Akihito.
- These Hands Have Killed: At the end of episode 2, she tells Akihito not to get involved any further with her. When he asks why, she says that she killed someone before. Episode 3 reveals she killed a close friend, Yui Inami, a daughter of the family that took her in, after she was possessed by the Hollow Shadow.
- Token Mini-Moe: Shortest character of the main cast.
- Unbroken Vigil: When Akihito awakes from his coma, Sakura notes that Mirai hasn't left his side. Subverted - it's All Just a Dream.
Mitsuki is the youngest daughter of the Nase clan, a wealthy and powerful clan of Spirit Warriors, and shares the family power of creating cages, primarily defensive shields. She also uses a rodent-like youmu familiar in combat. Mitsuki is the president of the Literature Club and friends with Akihito; evidently this means she's constantly teasing him. However, underneath her initial unapproachable exterior is a Lonely Rich Kid who would very much like to have friends.
- Barrier Warrior: She can erect a cage, like her siblings. However, hers seems to be a bit weaker.
- Brother–Sister Team: She and Hiroomi take down a powerful youmu during the Calm.
- Childhood Friends: With Akihito. Although it's implied that Hiroomi and Mitsuki are less "friends" and more "guardians" to make sure Akihito's youmu side doesn't go berserk.
- Cool Big Sis: She eventually becomes this towards Mirai when they become friends.
- Mitsuki genuinely treats her nicely because she likes her and not out of a sense of obligation. In one of the Mini Theater shorts, Mitsuki even says Mirai "looks so cute when she's flustered" after teasing her.
- In the movie, Mitsuki is the one who recruits Mirai back into the Literature Club and is actively trying to get her and Akihito back together. She's even apparently been taking care of the bonsai in the clubroom during Mirai's absence.
- Deadpan Snarker: Particularly against Akihito and Hiroomi.
- Familiar: Uses a rodent-like familiar to combat youmu.
- Headbutt of Love: Shares one with Mirai at the end of the sequel film. It's mostly of a platonic/sisterly nature, though. Mostly.
- Just a Kid: This does happen to her because she is the youngest out of her family. She finally defies this in Episode 12 when she enters the fight with her siblings, Sakura, and Ninomiya against Miroku.
- Lonely Rich Kid: Izumi tells her in a flashback that as Spirit Warriors, they're always going to be alone, especially Mitsuki as she's a daughter of the powerful Nase clan. She isn't shown to have plenty of friends outside the main cast.
- Not So Stoic: Mitsuki is noticeably more emotional and openly affectionate whenever she's around Mirai. The lantern festival from episode 5 and the idol training montage in episode 6 are notable examples. Doubly so in the sequel film, and especially in the ending scene where she excitedly runs towards Mirai (who now has her memories restored) with tears in her eyes and tightly embraces her. This is perhaps the most emotional Mitsuki has ever been throughout the entire series.
- Ojou: She comes from a well-known and very rich Spirit Warrior family, although she doesn't act in a particularly haughty or refined way.
- Oral Fixation: Often shown eating a Chupa-Chups.
- Pet the Dog: Despite telling Akihito to avoid further contact with Mirai, Mitsuki treats Mirai nicely. Mitsuki helps the other girl find Ayaka's shop when the latter got lost and offered Mirai the gemstone after killing a youmu. Later on, she and Mirai become good friends.
- Ridiculously Cute Critter: Her youmu familiar.
- Sugar-and-Ice Personality: Hides genuine moments of kindness towards Akihito and Hiroomi under a cold, blunt exterior.
- The Stoic: She often tries to hide her emotions. But is sometimes not very good at it like when Mirai convinces her to go to the festival.
- Sweet Tooth: Almost always seen with a Chupa-Chup in her mouth or eating other snacks.
- The Tease: Ocassionally towards Akihito, joking that she'll confess her love for him in front of their class at graduation. Despite that, there's no other hints of any romantic feelings between the two.
- Yaoi Fangirl: Implied. She gets back at her brother for sending her resume into an idol group without her permission by putting a bunch of BL audiobooks on his phone.
Hiroomi is the middle child of the Nase clan and Mitsuki's older brother. Much to her dismay, this also means he claims to have a sister complex, and much of his interactions with his sister result in her reprimanding him for his behavior. (They really do love each other, though). He's also friends with Akihito, with whom he gets along spectacularly.
Hiroomi shares his family's cage-erecting powers. He also fights with his scarf, which is enchanted to erase parts of the user's body.
- Adaptational Personality Change: The anime makes him much goofier and greatly exaggerates his sister complex. Traits like him favoring novels about little sisters and having his own sister's voice as his ring tone are exclusive to the anime.
- Badass in a Nice Suit: Wears a black suit and trenchcoat in the movie, even when fighting. Makes sense because Hiroomi has to dress more formally after becoming the new head of the Nase Clan.
- Barrier Warrior:
- Creates a huge barrier to block the Hollow Shadow while simultaneously fending off numerous smaller youmu. In fact, barriers are his specialty.
- Makes a barrier to contain Akihito after his Superpowered Evil Side takes over. He is ultimately unable to maintain the barrier under Akihito's assault.
- Big Brother Instinct: For all his embarrassing siscon claims, he's quite protective of Mitsuki.
- Bishōnen: So far the greatest example on the show.
- Broken Pedestal: Spent his life wanting to be like his older sister Izumi. In Episode 12, he acknowledges that he has to move past this, because the same episode reveals Izumi harbors a shade in her body herself.
- The Chains of Commanding: In the movie, it's mentioned that the Nase Clan is beginning to crumble and more and more people are questioning their authority due to to Hiroomi's inexperience as the new head.
- Childhood Friends: With Akihito. Although it's implied that Hiroomi and Mitsuki are less "friends" and more "guardians" to make sure Akihito's youmu side doesn't go berserk.
- Covered with Scars: He's got some serious scars on his back. Episodes 4 and 5 reveal that Akihito did this to him after having lost control of his Youmu side. Episode 0 shows how it happened exactly.
- Declaration of Protection: A pretty mild one but he swears he'll protect Akihito and train until he is as strong as his sister.
- The Gadfly: He enjoys teasing Akihito way too much and actively creates situations that make him uncomfortable.
- Improbable Weapon User: His scarves work by erasing parts of the target's body. Justified, since they're probably magic.
- Incest Subtext: One-sided and played for laughs. He openly admits that he has a sister complex and enjoys reading literature that involve little sisters. His sister, on the other hand, does not appreciate Hiroomi's sentiments. He tones it down about the time the shows halfway point rolls around and it looks more like he has more of a Big Brother Instinct than a sis-con.
- Mr. Fanservice: Bishounen, had a shirtless scene. In the third Idol Trial short, he is naked except for his scarf. And the animators made sure we had a good look. They even played up the Ho Yay he had with Akihito to Akihito's displeasure.
- The Nicknamer: Hiroomi gives Akihito the nickname Akkey, to the latter's displeasure. According to Akihito, it makes him sound like a washed-up pop star.
- Nice Job Breaking It, Hero: In order to see if his sisters' goals are as benign as they seem, he sneaks into the family vault and does some investigating... And forgets to lock the door behind him. This gives Miroku the opportunity he needs to steal the Hollow Shadow's Yomu Stone and feed its power to his staff.
- No Sense of Personal Space: Invokes this towards Akihito because he gets cold extremely easy and uses Akihito's body heat to stay somewhat warm.
- Scarf of Asskicking: He actually uses it in battle. And he has more than one. We have seen four as of episode 7. He wears them because his powers as a Spirit World Warrior make him extremely sensitive even to the slightest cold.
- Strange Minds Think Alike: He and Akihito. Hiroomi's quirks aside, they are very, very much alike. They generally act like they practice their interactions with each other.
Spirit World Warriors
Akihito's eccentric mother, who's also a busy Spirit World Warrior and thus constantly away.
- Action Mom: She didn't let motherhood get in the way of her job as a Spirit World Warrior.
- Adaptational Curves: In Beyond the Boundary: I'll Be Here, her boobs are somehow bigger as shown when she's wearing her ninja costume. Whether she enlarged them herself or if it's a retcon is unkown.
- Amazingly Embarrassing Parents: She sends holographic post card messages to Akihito where she appears wearing skimpy animal-themed cosplays. Her son nearly passes out from embarrassment as several others watch said messages.
- Bunny-Ears Lawyer: Implied. She's downright insane when it comes to parenting, but other characters speak of her skills with reverence.
- Cloud Cuckoo Lander: Ayaka accurately describes Yayoi as a big-busted mother with a few screws loose.
- Cosplay Otaku Girl: Yayoi is introduced in a holographic post-card message, in which she is wearing a skimpy Cat Girl costume, using every Japanese cat-related pun possible. On career day, she dressed up in a panda suit and pretended to be one of the students.
- Eye Colour Change: Her eyes change change color between scenes. It's possible she's using colored contacts with her costumes, which she also changes between frequently.
- Gate Guardian: In Mirai-hen, she implies that she's the gatekeeper between the two worlds.
- Inciting Incident: In a sense, she's to blame for the entire events of the series. In Episode 0 she drops a capsule containing blood in front of Mitsuki, who shares that it came with a label stating that being cursed blood, it is effective in countering youmu Akihito, thus leading Izumi to seek out Mirai as a means to defeat Akihito for good.
- Interspecies Romance: Akihito's father is a youmu.
- Mum Looks Like a Sister: Her juvenile look certainly makes the impression that she isn't much older than Akihito. She is actually shorter than her son and his friends.
- Parents as People: She's always traveling, so her son has to live alone. But for all her nonsense, she does care about her son.
- Strong Family Resemblance: In the anime, she really resembles Akihito.
- Too Kinky to Torture: When Sakura said that she wanted to kick her, Akihito stopped her from doing so by saying that "she'd like it". He's right.
- Very Punchable Man: Her demeanor tends to annoy people so much that they want to kick her. In fact, in Episode 12, her own son slugged her a couple of times (albeit played for laughs). Later on, Sakura kicked her across the room when she reached her limit, and Ninomiya would had done the same if Sakura hadn't done so. Lastly, when Yayoi began to beat around the bush when questioned about her knowledge of Beyond the Boundary, Izumi stabbed her in the chest.
- Wacky Parent, Serious Child: The Wacky Parent to Akihito's Serious Child, what with her always embarrassing him with her childish antics and revealing outfits.
A member of the Inami family who has very little spiritual power, and must rely on a special weapon to fight Yomu rather than her own power. She can't remember who exactly gave it to her.
- Action Girl: Until she loses her weapon.
- Boom Stick: Her supposed weapon was a halberd with a cannon attached to the blade.
- Canon Foreigner: An anime-original character.
- Cast from Hit Points: Her weapon becomes progressively more powerful as it's fed youmu stones, but requires more and more energy from its wielder. Eventually, the weapon will consume its wielder if the user can't supply it with enough energy.
- Chainsaw Good: Her weapon has this function in close range combat, as seen when she slowly saws through Mirai's blood sword.
- The Comically Serious: She keeps the same deadpan expression in her funny moments.
- Deadpan Snarker: Has a deadpan sense of dark humour.
- Demoted to Extra: She was introduced as a scarily powerful and menacing character, but after losing her weapon and motivations, she is relegated to stand around on occasions and snarking from the sides.
- Easily Forgiven: Mirai pretty much overlooks how she was out to murder her once she gives up on doing so. They even become roommates.
- Foil: To Mirai, who is more emotional and has a stronger Sixth Sense. Solidified in their interactions after Sakura moves in with her.
- If You Kill Him, You Will Be Just Like Him!: She is told to kill Mirai to fulfill a mission and partly to avenge Yui's death. But Mirai fights back during their second encounter, and defeats her completely, while also telling her that killing someone wasn't going to bring back Yui, nor would her sister have wanted her to go down this path. This manages to stop Sakura from wanting to seek vengeance.
- I Just Want to Be Badass: Sakura has weak Spirit Warrior powers, unlike her sister Yui and Mirai. In an attempt to strengthen herself, she made a deal with Miroku. She would borrow a weapon that would increase in strength as it is fed youmu stones in exchange for killing Mirai.
- Kick Chick: Is rather fond of kicks - in fact, she dropkicked Akihito in Episode 10 and sent his mother across the room two episodes later.
- Lonely Rich Kid: Implied to be as much, as a member of the powerful Inami clan, moreso after her sister's death.
- Mix-and-Match Weapon: Her weapon appears to be either a sword with a long handle or a short polearm with a large blade, with rotating teeth and a gun that shoots green energy beams.
- Muggle Born of Mages: Lacks the powers of her sister and other members of her clan.
- My Sibling Will Live Through Me: Wants to be a Spirit World Warrior in place of her sister, despite the fact she lacks the Sixth Sense to do it.
- New Transfer Student: She transferred into Mirai's class so she could have more opportunities to kill her.
- Nice Job Breaking It, Hero: Akihito was possessed by the Hollow Shadow. Mirai would have been able to fight it without him getting involved if not for her pointless pursuit of murdering Mirai. Instead, Mirai was forced to stab him and spray him in her blood. Akihito's youmu instincts kicked and it wasn't pretty.
- Not a Morning Person: She has a hard time waking up, falls asleep when walking to school, and even sleeps during class.
- Not So Stoic: When Mirai vanishes.
- Perpetual Frowner: Doesn't smile very much.
- Shipper on Deck: After they become friends, she supports AkihitoxMirai.
- The Stoic: Often has an emotionless face.
- Sugar-and-Ice Personality: She's cold, calm and quiet by nature, but also a soft-hearted loving girl when you gain her trust.
- Unwitting Pawn: To Miroku, who gave her the weapon and told her to feed it youmu to strengthen it. She was entirely unaware of his true objective with it however, and gave it enough power for him to continue his mission.
- You Killed My Father: Subverted. Initially, it appeared Sakura is trying to avenge her sister Yui by killing Mirai, but really Sakura was trying to kill Mirai as part of a deal she made with Miroku.
A teacher at the school the main characters attend, she is a powerful Spirit Warrior with the ability to distort space. Unlike the primarily defense-based Nase clan members, her ability has many offensive uses.
- Action Girl: She's a famous Spirit Warrior.
- Adaptational Job Change: In the light novel, she is an unrelated mercenary working for the Nase clan. The anime makes her a friend to the Nase clan who also works as the main characters' classroom teacher.
- Badass Teacher: Her Establishing Character Moment in the anime has her flying into a large youmu that attempted to attack Akihito and Mirai. After it runs away, she chases after it, and defeats it a short time later.
- Combat Pragmatist: She obviously didn't give a damn about taking hold of Miroku in an attempt to blow off his arm with magic.◊
- Combat Stilettos: Primarily fights in heels.
- Dishing Out Dirt: Shizuku creates a wall of earth and cracks the ground underneath Akihito's feet when trying to defend herself and the others from his attacks.
- Facial Markings: Wears pink facepaint in a kanji pattern on her cheekbone when fighting.
- Genki Girl: An adult version.
- Good Old Fisticuffs: The only Spirit Warrior or Action Girl that doesn't fight with a weapon, and is even shown taking out a hoard of youmu during The Calm with her bare hands.
- Hard-Drinking Party Girl: Loves to drink alcohol as much as possible when off work.
- Hot-Blooded: Threatened a student when he suggested that she was taking time off to get married. Nino-san reduced the poor boy to terrified whimpering.
- Hot Teacher: She also works as a teacher.
- Kick Chick: Her style is based around martial arts.
- Martial Arts Headband: A black one as she is in into martial arts.
- Super Strength: Creates craters into the ground like it's nothing. She even wakes up a sleeping Sakura in class with a light tap of her heel, propelling the girl's desk a foot off the ground.
- Stood Up: In Episode 5, Ninomiya is shown alone reading a text message by her date who cancelled on her. It's a short moment but it's not Played for Laughs.
An Interrogation Officer in the Spirit World Warriors Society who comes to visit the Nase family in order to monitor the Hollow Shadow.
- Adaptational Superpower Change: In the light novel, his main ability is the kotodama, a powerful spell that allows him to turn his words into reality. In the anime, he uses the special anti-youmu weapon he lent to Sakura, as well as his own parasitical youmu abilities.
- All for Nothing: He doesn't manage to kill off a single lead character in his quest to end the world.
- Back from the Dead: Apparently survived the explosion and returns as the main antagonist in I'll Be Here. Subverted when it turns our Miroku was Dead All Along (with a mummified corpse to boot) and it's really the parasite youmu combined with his consciousness pulling all the strings.
- Big Bad: literally the mastermind of almost everything that occured in the series & movie
- Body Horror: Not that it bothered him, the Hollow Shadow's influence begans to form through his body, even below his right eyes.
- Crouching Moron, Hidden Badass:
- Easily dispatches a youmu without moving, impressing Izumi. He plays it off as nothing important.
- He takes on Ayaka in her youmu form with minimal difficulty. Note that Ayaka is considered extremely powerful, on par with warriors of the Spirit Warrior Society. However, he fought her during the Calm, where Ayaka's powers were significantly weakened.
- For the Evulz: Even after he loses his chance at obtaining Beyond the Boundary, he still goes out of his way to amplify its power in order to lessen Mirai's chances of defeating it from within and hinder everyone else's efforts to help her, simply because it "suits someone like him."
- Freudian Excuse: Implied in the Mirai-Hen movie. He says that he hates "the world and everyone who rejected him." What this means is never further elaborated upon, but it seems like Izumi was the only person he knew who didn't treat him with disdain, leading to an obsession with her and a desire to end the world in such a way that they would always be together.
- I Surrender, Suckers: Upon being defeated by Izumi and knowing that his plan can no longer succeed, he proceeds to blow himself up in a massive explosion.
- Jerkass: He's callous, is not above murder, and is willing to do things that could potentially end the world seemingly For the Evulz.
- Love Makes You Evil: Possibly, as shown in the sequel film.
- Mr. Fanservice: Even Ninomiya comments on how dashing he looks.
- Obfuscating Stupidity: Subverted; he's clearly hiding something and Izumi is immediately distrustful of him.
- Omnicidal Maniac: His overall motivation. The only thing that really changes as the story goes on is how he plans on bringing it about. At first his goal is to either take over or set off Beyond the Boundary by using Akihito, its host. It later becomes stopping Mirai from sealing it. In the Mirai-Hen movie it becomes spreading the Youmu he and Izumi host to Mirai while also breaking her emotionally, which will advance said Youmu's possession, allowing him to take control of her and use her to set off Beyond the Boundary by killing Akihito without killing it.
- Oral Fixation: Seen sucking on a juicebox on occasion.
- The Pirates Who Don't Do Anything: The anime introduces him as a interrogation officer, but he is never doing anything remotely resembling to this. His ability to manipulate people does hint he knows a lot about human psychology, though. (The confusion might come from the series's usage of a rather anticuated word for inspector, samonkan, which can be literally translated as "inquisitor" or "interrogator".)
- Sharp-Dressed Man: Sports a waistcoat and a bolo tie.
- Stuff Blowing Up: Tried to blow up Hiroomi in an abandoned bus and attempted to do the same with Izumi in a fashion of Taking You with Me.
- Taking You with Me: After pissing off Izumi to the point of her slashing him in half and realizing his plan has been foiled, he blows himself up and tries to take Izumi with him. He fails.
- With Great Power Comes Great Insanity: Has his moments of looking a bit off, especially after revealing the youmu he put inside of him.
- Would Hurt a Child: He doesn't hesitate to dish out on our protagonists, who are in their teens.
The eldest sibling and acting head of the powerful and wealthy Nase clan of Spirit World Warriors. Her ability to generate barriers are very powerful.
- Action Girl: She is a Spirit World Warrior, and an exceptionally powerful and skilled one to boot.
- Aloof Big Sister: Seems to be pretty cold to her siblings.
- Aloof Dark-Haired Girl: Cold, wealthy, stoic, scheming, and powerful.
- Badass Longcoat: Sports a trenchcoat over her main attire.
- Barrier Warrior: Like her siblings, Izumi's main power is creating cages.
- Bifurcated Weapon: Her naginata can be separated into two separate swords.
- Bitch in Sheep's Clothing: She'd been planning Akihito's murder since before the first episode (though as the Episode 0 prologue revealed, she's been trying to have him dispatched for even longer). She was the one who sent Hiroomi to "subdue" him, which resulted in the scars on his back.
- Brainwashed and Crazy: In the movie, thanks to Miroku's parasites youmu.
- Broken Ace: She's one of the most powerful members of the cast, but that's only because of the youmu inside her.
- Combat Pragmatist: She's been planning Akihito's murder for a very long time now because he's the host of the powerful Beyond the Boundary. This is primarily because the Society of Spirit World Warriors is also after him. She planned to have Mirai do all of the dirty work.
- Combat Stilettos: Just like Ninomiya.
- Easily Forgiven: She gets off pretty much scott-free after arranging Akihito's assassination and then convincing Mirai to sacrifice herself in order to achieve her ultimate goal of destroying the Beyond the Boundary—which, by the way, did not work. Justified in that her actions make a lot of sense when you look at things from a pure logical standpoint, and she's clearly not ecstatic about the job either.
- Flash Step: One of many techniques she utilizes in combat.
- I Did What I Had to Do: Her motivations for trying to kill Akihito had nothing to do with him, but everything to do with how it was the only way to defeat the Beyond the Boundary, a youmu capable of destroying the world that he was hosting. She's not exactly excited about this part of her job.
- Lady of War: She fights very elegantly, and even uses a naginata for bonus points.
- Mum Looks Like a Sister: Inverted, interestingly unlike Yayoi. She could reasonably pass for Hiroomi and Mitsuki's mother in appearance.
- Naginatas Are Feminine: She uses a double-bladed naginata.
- Nice Job Breaking It, Hero: Remember how Akihito lost control of his youmu side and attacked Hiroomi? She was the one who told Hiroomi to do something that would set off his Youmu side in the first place. The incident nearly got her little brother killed and left Akihito severely traumatized.
- Obviously Evil: She's stoic, reserved, elegant, distant to her little sister, focuses a lot on reputation, and stole the Hollow Shadow from Mirai. But subverted when it turns out she's actually the closest thing to a Big Good shown in the series yet.
- Peek A Bangs: Of the "concealing something" variety.
- Well-Intentioned Extremist: She's been plotting to have Akihito killed so Beyond the Boundary can't destroy the world.
The deceased elder daughter of the Inami clan.
- Demonic Possession: By the Hollow Shadow.
- Nice Girl: Very sweet and friendly.
- Only Friend: She was the only person who befriended Mirai regardless of her family's cursed abilities.
- Posthumous Character: She died before the start of the series when Mirai tried to fight the Hollow Shadow.
Ayaka makes a business out of appraising youmu and paying Spirit World warriors for the crystals youmu leave behind. She's also one herself, but prefers her kimono-sporting, humanoid form over her fox form.
- Adaptational Job Change: In the light novel, her Muggle business is a wagashi confectionery shop. The anime changes it to a kissaten café and a photo studio.
- Asian Fox Spirit: She's a kitsune youma, though she prefers being in her human form.
- Barrier Warrior: Is also capable of setting up barriers like the Nase clan. When she and Hiroomi team up in Episode 4, it's her job to repair the cage Hiroomi keeps up.
- Breath Weapon: In her Kitsune form.
- Covert Pervert: Apparently also sells provocative pictures as a side-business. She has nudes of her sister, it seems. She also frequently tries to get Mirai to pose nude for her in exchange for "XX thousand yen". Even Akihito tells Mirai not to listen to her sugared words.
- I Am Not Left-Handed: Even when The Calm took place, she was still powerful enough to hold her own against Miroku.
- Kimono Is Traditional: Wears an elegant kimono.
- Took a Level in Jerkass: In the I'll Be Here movie, towards Hiroomi. Justified in that she thinks he isn't taking his job as the new head of the Nase Clan seriously enough and his indecisive leadership could force their alliance to crumble.
- Troll: She seems to get a kick out of intentionally misleading Mirai and Akihito regarding certain youmu when they come to her for hunting jobs.
- Voluntary Shapeshifting: She can shift between her human form and her true fox form. Even during the Calm, she shows herself to be fairly powerful.
An anime-only character, Ai is Ayaka's cute younger sister.
- Bakeneko and Nekomata: She's apparently a (friendly) nekomata, but usually takes the form of a human.
- Bitch in Sheep's Clothing: Only in the Idol Trial shorts.
- Canon Foreigner: An anime-original character.
- Deliberately Cute Child: In the Idol Trial shorts.
- Hidden Buxom: Implied, as Mirai is pretty shocked at her bust size in her nude photos.
- Voluntary Shapeshifting: A nekomata in human form.
A very powerful youmu whose power distorts the space around it, resulting in the world gaining a purple tint and its outward appearance as a huge shadow, earning it its name.
- Attack Its Weakpoint: What you have to do to actually bring the fight into more even ground in the first place, then again to finally kill it.
- Combat Tentacles: The core's main form of attack.
- Demonic Possession: Twice. First to Inami Yui, and then to Akihito. In the later case, it was chased out before it could fully take over.
- Disc-One Final Boss: The Big Bad for the first half of the series.
- Money Spider: As put by Shizuku, killing it would allow one to live almost like a king for a year.
- Psychological Torment Zone: It's insides consist of massive labyrinths crafted from the memories of the intruders, and it also preys upon the regrets and fears of its victims.
- Screw This, I'm Outta Here: What it attempts to do once Akihito's body is damaged enough, as per his Batman Gambit.
- Shapeshifter Guilt Trip: Takes Yui's form to guilt trip Mirai.
- The Worf Effect: For such a massive and powerful youmu, it went down rather quickly. The methods required to defeat it directly cause the emergence of Beyond the Boundary in Akihito again.
- You Cannot Grasp the True Form: The huge shadow is actually the result of space being distorted around the actual youmu because of how powerful it is. Once the youmu is sufficiently weakened by Mirai, the shadow disappears and it's true form is revealed.
Beyond the Boundary
A youmu of inconceivable powers. Born of the negative feelings of countless humans, this massive entity has the power to destroy the world with ease.
- Antagonist Title: The titular "Beyond the Boundary".
- Anti-Magic: On numerous ocassions it has shown the ability to negate the powers of spirit warriors, including Mirai's blood, even during the Calm.
- Demonic Possession: This was Akihito's so-called "youmu side". Therefore, every time it appeared it took over was an instance of this trope.
- Eldritch Abomination: To a higher degree than even youmu like the Hollow Shadow. It's power is such that even greatly weakened by the Calm, Akihito is STILL a Person of Mass Destruction when possessed by it.
- The End of the World as We Know It: What it can bring about if left alone.
- Hell Is That Noise: A loud, booming sound that only Akihito can hear, presumably due to having harbored it.
- Nigh-Invulnerable: The only thing that could supposedly kill it was the blood of the Kuriyama clan. And while it was said blood that was capable of extracting it from Akihito, what stopped it in the end was being absorbed back into Akihito.
- No-Holds-Barred Beatdown: On the receiving end of one from Akihito in episode 12.
- Playing with Fire: Inside or outside Akihito, this seems to be its most common form of attack.
- Psychological Torment Zone
- Reality Warper: Hoo boy. Whenever it manifests, strange phenonema abound. The ground becomes reflective, like looking upon a lake, and gains a strange tint. Youmu grow very active. When it was freed from Akihito, it created a new dimension and stayed there to save itself from death, then began to absorb the powers of spirit hunters and youmu alike in order to sustain itself. Its insides feature an almost exact copy of whatever it is reflecting, and it can be basically anywhere in it at once to attack.
- Sealed Evil in a Can: It had been sleeping inside Akihito.
- Sealed Inside a Person-Shaped Can: Since before the show, it had been sealed inside of Akihito for an unknown amount of time, emerging whenever his human consciousness grew weak due to extreme amounts of physical damage. This youmu's mere presence was also responsible for Akihito being Nigh-Invulnerable.
- Super Empowering: Akihito having this thing inside of him is what HIM Nigh-Invulnerable in the first place.
- You Cannot Grasp the True Form: The closest thing it had to this (and what it defaults to, really) was Akihito's appearance. Without that, it's basically a gigantic reflective surface.
- Walking Spoiler: The significance of this being to the story is ridiculous.