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Published:
2026-05-17
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2026-06-30
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4/?
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The Argonaut, the Wolf, and the Sun

Summary:

Bell Cranel. Izuku Midoriya. Tanjiro Kamado. Three boys who grew up together in a small, unnamed village. Separated for a few years, they reunite in Orario's dungeon, each in a familia of three virgin goddesses. And now? Now they'll join together, in order to become the heroes they aspired to be as kids. Oh, and pick up various girls in the dungeon; whether they know it or not.

Notes:

So… this has been playing in my head for a while now. Been actively debating/fighting whether I should write or not. With all these fics I've been writing/trying to write, surely adding a new one wouldn't be smart, right?

Then I started reading "Heir of the Hound". Then "Multiverse Theory is a Bitch" (Both fics by Supreme_King_Nero). Both led to Epic the Musical. On the side, I watched Demon Slayer: Infinity Castle.

Don't know which ultimately did me in. But yeah, this fic idea pretty much cemented itself in my head; and evidently, I caved. So here we are, with a MHA x Demon Slayer x Danmachi crossover. Primarily set in the Danmachi universe. I hope you enjoy.

Disclaimer: I do not own My Hero Academia, Demon Slayer, or Danmachi.

Chapter 1: Two Rabbits and a Sun

Notes:

(See the end of the chapter for notes.)

Chapter Text

So… want to hear a hero story?

We have plenty of tales to go around. Plentiful heroes to talk about, from the Cowardly Argonaut, to the Shrewd Wolf, to the powerful Albert…

But how about we get into heroes in this age? Rarer, I know, but they are there. And some are as great as the heroes of old; from the mighty All-Might, to the ferocious Flame Tiger.

The one I'm about to tell… is of a trio of heroes. You may know them as the Holy Maiden's Sentinels.

First is their leader. The Little Wolf, Argonaut's reincarnate, Regulus Arne, Ox Slayer…

Next is the strategist. The Rabbit-Cloaked Monster, the Wolf's reincarnate, Giant Butcher, the Viridis Sage…

And then there's the hunter. The Small Sun, Yoriichi's Descendent, Child of Brightness, the Rubrum Hunter…

Bell Cranel. Izuku Midoriya. Tanjiro Kamado. Three boys, childhood friends who joined together into the Dungeon; and together, quickly grew to be some of the most powerful adventurers out there. Three boys who went on to fight and defeat some of the most deadliest of monsters in existence…

And to start their story… how about we begin with a minotaur encounter?


"It's just me, myself, and I… Diving into this Dungeon… Joining the world you journeyed to…"

It's been two weeks since Bell entered the labyrinth city of Orario, in order to become an adventurer, pick up girls in the dungeon, and be the hero he aspires to be. Dreams that he had, ever since he was a kid… and dreams he shared with two others.

At first, he was rejected by every Familia he attempted to join, due to looking like a scrawny weakling. Got to a point where he was close to just giving up. But then… his goddess, Hestia, appeared; and offered him to be the first to be a part of her Familia.

It was an offer that he took immediately; and one that he'll remain grateful of for the rest of his life.

And now, after getting the standard guild equipment, as well as enough lessons from his advisor, Miss Eina, he set foot into the dungeon… though it wasn't as exciting as he expected.

"Dreaming of all these monsters that I've yet to get to fight…" Bell continued singing to himself, staring at the entrance to the fifth floor. An excited smile entered his lips, as he thought about being able to fight those very monsters. "But boy, I wish I could, so I could bring this world some light…"

He still remembered Miss Eina's lesson, how adventurers shouldn't be TOO adventurous. That he isn't ready to enter the fifth floor yet. But… with how easy the 4th floor monsters and above have been, he couldn't help but be a little curious! Surely a small look around wouldn't hurt, would it?

…A small chill went up his spine at the thought, but that was not enough to erase his eagerness!

"Nnnnngh! I'm sorry, Miss Eina…!" With a muttering apology, Bell hopped down into the fifth floor. He'll just take a look around, and that's it! If it gets too dangerous, he'll immediately come back up!

As he explored the fifth dungeon, he thought about the two others who shared some of his dreams. Childhood friends who have already gone on to their adventures… even if it wasn't in the Dungeon.

"Cause I'm stuck with your stories… But no clue where you are…"

He thought about his green-haired friend, a boy who was much smarter than he was, yet shyer than him. Someone who was found and picked up by his own goddess three years ago, learning to be some sort of warrior. A Warrior of the Mind.

"And no idea if you're dead or just too far.."

His thoughts went to his red-headed friend, the nicest guy he has ever met, with a nose that outmatches any hound. Remember how he and his entire family left the village two years ago, with no sign or info as to where they headed off to.

"Somebody tell me, come and give me a sign…"

For a moment, he stopped his walk, looking up at the rocky ceiling above him. Briefly, he couldn't help but see a pair of nervous yet hopeful green eyes, as well as a pair of overwhelmingly kind red eyes.

"If I fight those monsters, is it you I'll find?"

If he got stronger, dived further into this dungeon and became the hero he wanted to be… then could that lead him to his two best friends?


"So this is the dungeon…"

"The tower above it is so much bigger than I had imagined…"

Standing at the entrance of Orario's dungeon were two young men, both fifteen years of age. Both wore green, one wearing a cloak while the other wore a checkered haori. A bow and spear was on the back of the cloak wearer, along with a sword and knife sheathe in his belt, and spear in his hand; whereas the haori wearer merely had a katana on his side.

"So this is where Bell's scent is the strongest…?" The cloak wearing boy inquired with his friend.

His answer was an enthusiastic nod. "I can tell he came through here recently! And I'm certain he hasn't left yet!"

"And it lines up with what Miss Eina told us, too… alright, let's go in…"

And so, the two teenage boys took their first steps into the dungeon…


"If so then, give me sirens and some ogres! Give me dragons and a hydra!" Bell voiced out enthusiastically as he explored the fifth floor. "I know life and fate are scary, but I wanna be legendary!"

In most cases, he would be embarrassed voicing his thoughts out like this. But with no one around, and very few monsters in sight, he felt there was no harm in doing so.

"I'll fight the harpies and chimeras! The minotaurs, even a cerberus!" He even started swinging out his knife, pointing at those imaginary enemies. "I know life and fate are scary, but I wanna be-!"

A growl cut off his words. A very loud and very dangerous growl, with a large shadow accompanying it and covering the young adventurer. Both the sound and the shadow caused Bell to freeze before slowly, he looked up at the source…

That source being none other than a minotaur he just practically begged to fight.

"...L-L-L-Legendary?" Bell was able to squeak out.


"That's weird… there's very few monsters in sight…"

While it was only the first couple of floors, it's not usually this empty, was it? It felt deserted. As if the monsters were hiding away from something much more dangerous.

"I don't smell any nearby monsters either…" The checkered haori boy informed, his grip on his sheathed katana tightening a bit. "But Bell's scent is getting stronger. He must be down on the lower floor."

"But… they can't be right, can it? Didn't Miss Eina say he started out two weeks ago?" The hood wearer pointed out, his brow creasing in worry. "He shouldn't be delving that deep."

"Maybe he's getting stronger in a quicker amount of time…!" The checkered boy suggested optimistically. "And perhaps that's why we haven't seen that many-!"

Suddenly, the young man cut himself off, his words choking in his throat. That got a look of alarm, yet a tense look from his friend.

"What is it?! What are you-?!"

"A monster…! A strong one!" Was the answer given, red eyes sharpening as his grip on his blade tightened. "It's right down below, on the fifth floor!"

That had the pair of emerald green eyes widen beneath the hood. "What…?! But shouldn't… wait, does that mean-?!"

His own words were cut off by the sound of a terrified scream. What followed was the roar of what was undoubtedly a monster.

Both adventurers immediately ran to the source of the scream.


"Why, why, why, WHY?! WHY IS THERE A MINOTAUR IN THE FIFTH FLOOR?!"

When he said to give him minatours, he did not mean while he's still level one! He was far from ready to face any of the mid-floor level monsters! The only thing he can do is run and dodge every strike from the hulking beast!

Was this why there were so very few monsters in sight?! Damn it, he should've noticed something was wrong! He shouldn't have traveled deeper into the dungeon, thinking that with enough walking around, he'll find more! He should've listened to Miss Eina and not be TOO adventurous!

"EEEK!" With another high-pitched scream leaving his mouth, Bell ducked and rolled forward from another swing from behind. He didn't dare look back and continued his frantic run, hoping beyond all hope that he can lose the minotaur somewhere.

'If I can get back up to the fourth floor, then maybe-!'

That hopeful thought was stopped when he was confronted… with a dead end. A rocky wall with no openings or branching paths.

"A dead end…" He said numbly to himself, almost feeling as though this dungeon was mocking. He went pale when he heard a growl from right behind him.

'Somebody tell me…'

Immediately, he dropped to the ground, dodging the devastating punch that would've taken his head.

'Come and give me a sign…'

"GROOOAAAR!" The roar that left the Minotaur's mouth left the rookie adventurer shaking, as it punched the wall repeatedly in blind rage.

'If I fight this monster… is it you I'll find?'

He's gonna die. He's gonna die without picking up a single girl. Leave his goddess all by herself once again. Without ever getting the chance to reunite with his two childhood friends.

However, just as he was about to accept that fate… a cloaked adventurer suddenly jumped on the Minotaur's back; driving a spear through its shoulder.

"WROOOO!" A roar of pain left the Minotaur's mouth, the monster jumping up and immediately attempting to shake off its attacker. Said attacker remained stuck on its back, having a tight grip on their spear.

"Wh-Wha…?!" Bell could only stare at his unexpected savior with a rather dumb look.

But before he could process what was happening, the adventurer's hood suddenly flew off in the midst of the Minotaur's trashing; revealing a green-haired, freckled face that was hidden within the hood. A face that looked very familiar to Bell.

'Wait… is that…?!'

"Water Breathing, Third Form: Flowing Dance!"

Suddenly, a stream of water came out of nowhere, and swirled around the Minotaur's ankles, performing deep cuts in the back of them. That stream revealed itself to be yet another adventurer; the new adventurer sliding into a stop, twisting to face the high level monster.

That still gave Bell a view of the dark red hair of his second savior.

'No way… it can't be…!'

Unable to keep standing on its lacerated ankles, the Minotaur fell onto its knees, roaring out in pain-filled rage. That gave his first savior the chance to grab his knife and stab the Minotaur in the throat. The bull monster let out one last, strangled cry, blood dripping from its lips; before collapsing completely.

The collapse caused the adventurer on top to fall off towards Bell and his apparent partner. But rather than collapse into a heap, he managed to roll with the momentum and land on a hand and knee…

And the closer looked all but confirmed to Bell just who his savior was.

"Are you… al… right…?" The green-haired adventurer was about to ask, only to trail off when his green eyes met Bell's red ones. "...Bell?"

"...Izuku?"

Immediately, his other savior turned towards their direction; revealing his dark-red, yet bright looking eyes. Eyes that brightened up even further when they made contact with his own. "Bell…!"

"T-Tanjiro…?"

Both were older than he last saw them. Had scars across their faces that they never had before. Wore vastly different clothes compared to when they were living at the village. But there's no doubt in his mind that these are the two friends he grew up with since childbirth.

For a moment, the three boys merely stared at one another. Then, in near tandem, all three of them teared up.

""BELL!""

"TANJIRO! IZUKU!"

All three boys practically collided against each other, waves of tears leaving their eyes as they wrapped themselves in a three-way hug.

"It's been so long…!" Bell wailed out, the fear and happiness overwhelming him. "I thought I would never get to see you again!"

"I'm so glad I caught up in time…!" Izuku cried with equal elation, as he produced the rivers of tears he was known for. "I wouldn't know what I would've done if that Minotaur killed you!"

"It's so great to see you two again…!" Tanjiro bawled, producing the least amount of tears of three; but no less creating a river himself. "That we were able to reunite again!"

It took a little bit for the three to finish crying their hearts out. But those cries eventually lowered into sniffles; and soon, they were calmed down enough to pull away from one another.

"It's good to see you again, Bell…" Izuku stated, a watery smile across face. "It's been a long time…"

"Y-Yeah…" Bell nodded, slightly shivering. "If you and Tanjiro weren't here… if you didn't show up in time…"

"Hey…" Tanjiro cut in, squeezing Bell's shoulder in comfort and reassurance. "Don't think about it. Let's just be glad that we got here on time."

"We should probably leave the dungeon for right now…" Izuku advised, pulling away from the two and got into a more alert stance. "I don't know how such a Minotaur got up the upper floor, but there could be more of them. Or other high level mon-"

"Um, there's no need. We cleared out all the other Minotaurs on the upper floor."

Immediately, Tanjiro and Izuku swirled around, getting into defensive stances. Those stances softened when they saw that it wasn't a monster; but a golden haired adventuress. A very beautiful golden haired adventuress, with eyes of that same color, light armor and a white dress, and a face that one would consider doll-like.

Immediately, two out of three boys recognized this unparalleled beauty.

"The Sword Princess…?" Izuku gasped, lowering his spear. Even before arriving in Orario, he recognized the rising star of the Loki Familia. A level five high-ranking adventurer, who was able to become level two in just a year, and become one of the best swordsmen in Orario. Someone who is considered a flawless beauty, that rivaled even goddesses.

That beauty, of course, had Izuku's, as well as Tanjiro's, cheeks reddening. However, both were able to keep their cool; and not get dumbstruck by her beauty.

Bell, however…

The moment the white-haired novice made eye-contact with the golden-haired veteran, time seemed to freeze for him. It felt like his heart was struck, stopping and quickening at the same time. His already rattled mind became a whirlwind, yet no words seemed to form. His breath was close to quickening, yet he felt as though they stopped.

He could even swear he felt and heard some sort of zing in his mess of thoughts…

Unknown to him… that girl was feeling very similar things he was.


So… three brothers reunited, two of them saving the youngest of the trio. The youngest finding love at first sight with the Sword Princess herself, at a time when he was just a novice adventurer. A good little beginning for the Maidens' Sentinels, wouldn't you say?

And it's from there… those three will quickly grow into the heroes you all know. This world's greatest heroes.

Notes:

And that's the end. I hope you guys enjoyed this chapter. A bit short compared to what I usually write these days, but this felt like a good place to stop. A small, little prologue for the adventures these three cinnamon rolls will have.

As you'll probably imagine, if you read my previous fics and with this crossover set in the Danmachi universe, this'll be a harem fic. I haven't set all the exact pairings yet, but you can imagine I'll go with classic ones; such as Izuku/Ochako, Bell/Ais, Tanjiro/Kanao… DekuMeli and BellRyu… and of course, the three boys will be paired with their goddesses. As for the goddesses Izuku and Tanjiro are with? Some of you can probably guess already from the hints I put in, and by process of elimination.

So, let me know what you guys think of this chapter, and what you hope to see in the future. I got various plans for the direction these three MCs will go, but I'm open to suggestions, from plot ideas to ship proposals. Leave comments, kudos, and bookmarks, and I will see you later.