Into the Deepest, Most Unknowable Dungeon (2025)

"In this Mature-rated take on the popular isekai fantasy genre, a man journeys into the darkest, squishiest depths of a goblin-filled dungeon in another world! Former office worker Jean finds himself transported into a land where even armies have failed to conquer the FukaFuka Dungeon. With no magic cheat codes and no secret knowledge, Jean must battle goblins and seek glory alongside a cast of voluptuous warrior women!"

 Former office worker Jean finds himself transported into a land where even armies have failed to conquer the FukaFuka Dungeon. With no magic cheat codes and no secret knowledge, Jean must battle goblins and seek glory alongside a cast of voluptuous warrior women.

"The Deepest, Most Unknowable Dungeon is the deadliest stretch of ground in the new world into which Jean has been reincarnated. Even the top-ranked Holy Saint Slaughterer, the Queen of Darkness, and the Bow King are unable to defeat the demihuman hordes, or conquer the dungeon. But using Earth knowledge from his former life, Jean may just be able to develop the ultimate weapon-an arrow that can pierce any armor-and change the game forever!"

The Deepest, Most Unknowable Dungeon is full of secrets-and dangers. Kukoro, Mexy, and Ceres come to terms with captivity as Jean continues to hone the skills of his all-female party. Meanwhile, Cross learns more about the mysterious Holy Saint Slaughterer.

THE TERROR OF THE WHITE MASKThe blind Guide named Bato has her heart set on romance, and with a bit of advice from a pair of cheeky teenagers, she's doing everything she can to seduce the apple of her eye. Yet not all is well in the lands around Aegis. The redcap known as "White Mask" has long been the bane of its adventurers, and now he's been sighted once again. Ruthless, elusive, and seemingly invincible, he's claimed the lives of countless humans around humanity's walled fortress city. Jean is destined to come face-to-face with this monster of a man-hunter, and their collision will be a battle to remember!

There is one place that has withstood attempts by every army to conquer it-the city-sized labyrinth known as the Deepest, Most Unknowable Dungeon. But now, after dying on Earth as a young temp worker, Jean is reborn into the world with a fascination for its most infamous dungeon. With the right training and the most carefully chosen set of lustful comrades-in-arms, he may have the chance to accomplish the impossible and become a legend in a new fantasy world!

THE SWORD PRINCESS AND THE HOLY SAINTMere human strength is often not enough to deal with harsh and unyielding dangers—especially if you’re a woman. Yearning for a way she can distinguish herself as an adventurer, Aro devotes herself to engineering and invention, perfecting a new type of arrow the world has never before seen. Meanwhile, fresh from her encounter with Rapier, the Sword Princess Katana decides the time has come to end her adventures and return home. Deeply shaken by their fateful meeting, Rapier now seeks guidance on how to deal with her new rival...

A FATE WORSE THAN DEATHKukoro is brought to the Orc Empire as breeding stock! There she meets Scion, a heretical scholar, and learns the details of goblin technology—can she escape with the intel, and does she even want to? Meanwhile, Aro regains her confidence after the success of her bola shooter, and we meet Sei, the "Hero of the Holy Sword' who wields miraculous power and speed. Jean and his party set out once again into the untraveled lands of the Dark Continent, to go balls deep into the strange and unknown terror of the war between man and orc!

MAN VERSUS NATIONJean and his party traverse the Untraveled Lands and make an immense discovery! Sei puts her strength to the test in a mock battle against her friends to prepare for the Holy War! In the lands of the demi-humans, the breeding pens are filling up. With no magic and no cheats, Jean has only his allies and his indomitable will—can he get strong enough, fast enough, to fight back against an entire country of monsters?!

As Jean's party delves into the lower dungeons to explore unknown territory, the recently resurrected White Mask Blond Hair takes aim at a new goal-capturing the fortified base in the Forest of Death! But Jean and the girls are traveling a route that brings them in sight of the very same base! Will they encounter their own deaths?! No magic! No magic! No cheats! Delve deep, balls deep, into this isekai adventure!

ATTACK THE HEAD!Jean and the girls stumble upon the waterlogged remains of an ancient underground civilization...and encounter the many-headed hydra! But these are no mere beasts—more heads means more brains, and soon it is siege tactics and war between humans and cunning, nigh unkillable, monsters! No magic! No cheats! Get balls deep in this isekai adventure, where intelligence and instinct collide!

VICTORY THROUGH MASSIVE DEATH!Confusion, deceit, hubris! When the old methods of containment fail, open war between humanity and the massive, hyperintelligent hydra is inevitable! The beginning of war may bring about the end of civilization; the end of war can lead only to new and bloodier conflicts! With no magic, no cheats, and nothing to turn to but their own resources and skills, the reincarnated hero from another world and his sexy allies must go all out in this hardcore adventure!

FORCE RECON!The Forest of Death Fortified Base was ringed with ballistae and stuffed with troops, but fell all too quickly thanks to White Mask Blond Hair’s audacious stratagem! Jean’s Party and the Archbishop are shaken by this news, but Sei, the Hero of the Holy Sword, brimming with confidence, attempts a “power reconnaissance”! They may not have magic or cheats, but there are plenty of blades and fangs in this lucky thirteenth volume of hardcore adventure!

THE SAINT OF SLAUGHTER!The archbishop and his troops are trapped in the forest and surrounded by deadly arachnoid enemies! Rapier, the Holy Saint, appears in the nick of time to bring about a miracle of God with her exquisite sword dance! The secret of the hero Sei’s abilities, and so much more of her, shall be revealed. But this is a world without magic or cheat skills...so will even the slashing swords of a saint be enough against hundreds of eight-limbed opponents?!