Somewhere in Europe, late at night.
"Haaa!"
"Amen!"
The holy sword Excalibur, split into seven fragments, was wielded by two girls: Xenovia Quarta and Irina Shidou, warriors of the Church.
Both devout Christians, wielders of Excalibur fragments, and of the same age, they had grown close while carrying out shared missions, despite Xenovia's Catholic and Irina's Protestant affiliations.
Before them stood a monstrous creature, unmistakably a "Devil." Six skeletal minions had already been dispatched. The Devil itself was no match for the two in their current state.
Three shadows observed them from a distance: the Demon God Pillars Andras, Kimaris, and Zagan, disguised in humanoid forms.
The 72 Pillars of Solomon, mysteriously revived from another world, had much to do, but analyzing the strength of various factions was a priority. These three were tasked with investigating the Church's forces.
"Confirming, Andras… that's Excalibur?"
"So it seems."
"…Impossible. That dull blade, a divine weapon? Merely sharing the name, perhaps? No, it was split into seven, wasn't it? Kimaris, what's the deal?"
"Destruction, transparency, transformation, illusion, speed enhancement, blessing, control over living beings… None exceed childish tricks. The wielders aren't even Heroic Spirits—barely shadow casters. They'd only match a Shadow Servant, let alone Velber or its vanguard."
"According to Asmodeus's investigation, there's no trace of Velber's invasion 14,000 years ago on this planet."
In the Demon Gods' world, an extraterrestrial entity, Velber, invaded 14,000 years ago. The power that repelled its vanguard, the White Titan Sefar, became known as Excalibur.
If no extraterrestrial attack occurred, Excalibur or equivalent power would be unnecessary. Yet, something felt off.
"Still, King Arthur and the Knights of the Round Table exist in this history. Moreover, the Pendragon dynasty persists, even in this era devoid of mystery. …Though, the heir apparently ran away."
"The 'Sword of Selection' was taken during that, wasn't it? The 'Sword of Victory' was split and held by the Church. The most concerning 'Sheath' is missing."
"Thus, their threat level is extremely low."
"This world has no 'Throne.' Hence, no Heroic Spirits. Instead, those who inherit the souls of religious or mythical heroes are born, rejecting reincarnation."
"However, those inheriting souls don't fully retain their past lives' talents, memories, or experiences. Combined with Sacred Gear wielders, they could be troublesome…"
This world has "Sacred Gears," innate abilities bestowed solely on humans by the God of the Bible—a blessing and a curse. Among them, the thirteen most powerful, capable of slaying gods, are called Longinus.
Detailed data on Longinus is scarce. Most are unaccounted for—either their wielders are unawakened, secretly held by factions, or hidden by deception. The four supreme Longinus, including the "Spear of God-Slaying," the "Mist that Covers Nations," and the "Vessel that Creates demonic Beasts," are untraceable. The one known wielder belongs to the Church.
"The Church's strongest exorcist, Dulio Gesualdo. Given his background and personality, we might recruit him. Should we propose it to the Control Center?"
"Is it worth it? …I'd rather focus on finding the Holy Grail. The Church might have clues."
The Longinus "Sephiroth Graal," distinct from the omnipotent wish-granter or infinite mana device, specializes solely in manipulating life. Though called a Grail, it differs from the relic that caught the Savior's blood. As a Sacred Gear, its creator is the God of the Bible, so it's not exactly "false."
"Important, but off-topic. Andras, aren't you getting too personal?"
"Can't help it! I don't want to die! Not twice! Since I've been revived, I want to savor this 'self' forever,."
"What revived us, anyway?"
"Who cares? Speaking of the Church and holy swords, there was the Holy Sword Project, a human experiment. The project's leader was exiled and vanished, but there are surviving subjects. Their insights could be valuable."
"…Don't tell Flauros."
"He's investigating a town ruled by a Satan's kin. Baal mentioned testing Assassin there."
In Japan's Far East, a local city houses Kuoh Town.
Once managed by the Baal and Gremory families, former members of the 72 Pillars, it's now the territory of Rias Gremory, heir to the House of Gremory.
Rias Gremory, sister of Satan Sirzechs Lucifer, is a prodigy among her generation. Despite not yet being an adult Devil, she's earned the title "Crimson-Haired Ruin Princess." At Kuoh Academy, she poses as a third-year student and Occult Research Club president, enjoying a human-like life. That her lifestyle as one of the "Two Great Onee-samas" is far from a typical high school girl's is beside the point.
There's a backstory to Rias managing Kuoh Town.
Before her, Clelia Belial, cousin of the Rating Game's absolute champion, "Emperor" Diehauser Belial, oversaw the town. She fell in love with a Church warrior, Masayoshi Yaegaki. Corrupting an apostle might align with a Devil's nature, but their genuine love was unforgivable to both Devils and the Church. The exact trigger is unknown to outsiders, but their elimination was decided.
Forbidden love and kin-slaying were known only to direct parties and select higher-ups. Silence was enforced, and inconvenient truths buried. Everyone chose to hide and forget.
The Devils had additional reasons to kill Clelia, but that's irrelevant here.
The issue is the significant time gap between Clelia's death and Rias's takeover. As Church affiliates fled, Fallen Angels took root in Kuoh Town.
The Fallen Angels' de facto leader there is Raynare, with subordinates Donaseek, Kalawarner, and Mittelt, plus former exorcists abandoned or betrayed by the Church.
Until today, they'd used an abandoned church as their base.
Until today.
"…What is this?"
Baal in humanoid form muttered with irritation seeping into his voice.
"A territory with two Satan kin who rose by merit, not blood. And the Fallen Angels' forces here are this weak?"
Before him lay the corpses of Fallen Angels and their followers.
"It's easy to deem Fallen Angels weak, but… did they have reasons not to station stronger forces here? Underestimating Satan kin? This town's past might hold secrets. Assassin, what do you think?"
The only other standing figure, called Assassin, wore a bizarre outfit—a black cloak and an eerie mask, a "monster" in a different sense from Baal.
"Master, I don't care. My songstress isn't here. That's all that matters."
"As expected. Your obsession is why I chose you as my Servant. Your unending song of unrequited love holds the key to fulfilling my hatred. …I'll check Flauros's data on this town later."
"Impossible…"
It was Raynare, the black-haired Fallen Angel, collapsed on the floor.
"I'm a supreme Fallen Angel! To be defeated by incomprehensible freaks like you—!"
This wasn't supposed to happen. She was meant to rise higher, serving the great Azazel and Shemhazai to become a supreme Fallen Angel. To that end, she took in Asia Argento, wielder of the Sacred Gear "Twilight Healing," capable of healing Fallen Angels, at this church. She planned to extract the Sacred Gear, claim it, and become a healer of Fallen Angels. But—!
Incidentally, at that moment, Flauros had retrieved Asia. Whether her guidance to the Temple of Time was fortune or misfortune would be clear in about six months. Raynare would never know.
"So, Master, what now? This woman isn't my songstress. The decision's yours, client."
"There are plenty of ways to investigate. She doesn't seem promising for useful information. That human kid faking sleep over there looks smarter."
"…Oops, caught me! I was confident in my playing-dead act!"
"Tch, Freed! Protect me! You serve me!"
"No way. In this situation? I can barely save myself. Always thought this, but you're hot but kinda dumb, huh?"
"Torture's a hassle. —Kill her."
"Understood."
With theatrical flair, Assassin spread both arms.
"Noble Phantasm fragment deployed. Behold, my song sent from hell."
Suddenly, a massive pipe organ appeared, fitting yet unfitting for a church. No, it was utterly unsuitable, even for a church used by fallen beings. A grotesque instrument, its pipes crafted from human corpses.
"You'll never sing again."
Yo! I'm Issei Hyoudou! Everyone calls me Ise!
I enrolled at Kuoh Academy, a school with tons of girls, dreaming of a harem. Nailed the entrance exam, but I'm not popular at all. Thought a girl-heavy school meant easy girlfriends, but they all flock to the hot guys! No harem, no girlfriend even! Worse, I'm one of the "Perverted Trio," despised like poison by girls. This wasn't my plan! I aimed for a sexy, boob-filled high school life!
Finally got a girlfriend, Yuma Amano, but she killed me at the end of our first date. Turns out, she was a Fallen Angel after the Sacred Gear in my body. They kill Sacred Gear wielders like me before we get strong.
I died once, but the prez—Rias Gremory—revived me as a Devil. Literal Devil: magical power, bat-like wings, weak to light. The bad guys in stories.
I was shocked Devils and Fallen Angels are real. Apparently, Sacred Gears were made by the God of the Bible. Thanks for the nuisance, God.
Modern Devils have the "Evil Pieces" system, turning other races into Devil servants. That's how I became a Devil. Suddenly a servant, no longer human, but I'd be dead otherwise, so no complaints. I'm a "Pawn," the lowest rank.
But if I earn a peerage, I can have my own servants! And do anything with them! That means my dream harem of gorgeous girls! Boobs galore! I'll become the Harem King!
…Reality's not that sweet, though. I work hard as a Devil—fulfilling human clients' wishes for payment—but results are slim. Clients like me, but I rarely close contracts. Plus, my clients are all perverts or weirdos. Meanwhile, my fellow servant, the handsome Kiba, gets all the hot ladies. Damn you, pretty boy!
Today, I'm off to fulfill another weirdo client's request. When will I ditch this bicycle…?
Sure, I bonded with Morisawa-san over Dragon Ball, but clients like Mil-tan, the macho girl aiming to be a magical girl, Susan, who loves Japanese culture but in a bizarre way, or Limbo-san with his weird "Nnn!" speech—total oddballs.
…A while back, I met Asia, a Church nun and my natural enemy as a Devil. Her church was attacked by someone unknown. The prez and Akeno-san investigated, but the culprit's identity is unclear. The prez is pretty pissed—her pride's hurt, and it's unsettling for something to happen in her territory. Worrying about Asia probably makes me a failure as a Devil.
Oops, work time. She and I are enemies, and she didn't realize it. That's fine, right? Time to switch gears.
"Hey, I'm the Devil here for your request!"
"Welcome, Devil-kun."
Tonight's client is one of the saner ones. Introduced by Mil-tan, so I was nervous at first.
A nondescript guy nearing thirty. His unappealing vibe feels relatable.
"So, what's today's request?"
"Sorry for the repeat, but let's watch Milky again. Felt like rewatching the first episode with someone, but Mil-tan can't come today."
The client scratches the back of his neck—a habit I've noticed.
"…No other friends?"
"Mil-tan's the only one I can call to watch magical girl anime with. He… or is it he? I could invite his friends, but they're a bit much."
Sounds like an excuse. Geez, a grown man… wait.
"Now that I think about it, what's your name?"
"That's harsh! …Oh, maybe I never introduced myself. I had a nickname at my old job. Mind calling me that?"
"Sure, what's it?"
"Doctor Romantic."
He says it coolly, gazing somewhere distant.
"Call me Roman, with affection."