The Dungeon is a place of magic and mystery, a vast branching, underground labyrinth that has changed the world and the people who dare to enter its depths. Those who brave its challenges are rewarded with wealth, fame, and powerful classes that set them apart from the rest. Ken was determined to follow the footsteps of his family and become one of the greatest adventurers the world has ever known. He knows that the only way to do that is to get into one of the esteemed Dungeon colleges, where the most promising young adventurers gather. Despite doing fantastic on the entrance exam, when his class is revealed, everyone turns their backs on him, all except for one. The most powerful adventurer, Crimson, invites him to the one college he never thought he’d enter. Haylon, an all girls college. Ken sets out to put together a party and master the skills he'll need to brave the Dungeon's endless dangers. But he soon discovers that the path ahead is far more perilous than he could have ever imagined.

Classes continue at Haylon academy. Ken has identified who's behind the attacks on his Fieore and is determined to remove that particular problem, yet Haylon rules prevents him from taking it into his own hands. As they dive deeper into the dungeon, Crimson prepares him and the rest of the first years on how to camp in the dungeon. When their camping exercise is interrupted, Ken's done and this time he means business. Ken is going all out and his abilities tell him one thing, Ken was never trained as an adventurer. Ken was trained as an assassin.

Ken and party are training with his grandparents, preparing themselves to the next semester of Haylon. Yet, even after the Gransmens' deaths there are still plots from the Kaiming targeting Ken. After thwarting an attack on him at the Nagato Clan, Ken heads back to Haylon to get the strength he needs. After all, at the end of this semester, Crimson owes him almost a week of personal training and she sets ambitious goals for him. If he can complete them, he'll be going to the Elven World for summer break. Now Ken just needs to get rid of all these magazines that are cluttering up his inventory!

With Ken on the run and Crimson missing, he goes to the Elven world with Neldra and Fayeth to hide out until Crimson returns. Lady Rendral isn’t quite what he expected, her reclusive life leads her to happily accept Ken and Fayeth for the summer. But the future Empress of the Elven people isn’t without her own struggles. Political opponents push her and she hires Ken to dig up some dirt on those who would stymie her goals. Ken can see her struggle and works with Lady Rendral to topple her opposition.

Ken returns from the Elven World to another year at Haylon College. Yet, attitudes towards training have changed, the Naga attack has shifted priorities the world over and Ken finds himself and his fellow classmates pushed harder than ever before. The big four colleges no longer are going to focus on survival of their students, it’s time to push them and let the strongest shine. Which would be okay for Ken, if a new problem hadn’t cropped up. A monster that doesn’t appear in any of the records has been stalking him through the dungeon. The answer to it, might actually lie in Crimson’s past.

Reeling from the conflict with the dwarves, Ken and several Haylon classes move to an event on the 28th floor of a dead branch of the dungeon to prepare for the raid. While he’s busy training, his grandparents give him his first mission to assess and carry out on his own. Between Ken’s time of scouting out and investigating his target, he runs in with the other three schools and learns he’s not the only ace damage dealer. Pendulum, Trusk and the Royal Academy all have a student that’s a head above the rest of their peers. The pressure is on, especially when one of them is associated with Ken’s latest assassination target.

Ken and company embark on their first raid. Despite Ken’s powerful \[Liminal Speed] not all the boss fights are accommodating and the Haylon raid party must learn to work together in perfect concert. Prince Albar is unsatisfied with his defeat and plots to take down Ken and Elysara despite their Royal Censor guards. Yet, neither of them are prepared for the shakeup in the dungeon. All of the safety nets they’ve been training over are about to disappear.

Ken and company come back from summer break after arduous training for their third year at Haylon. No longer are they the fresh adventurers that once didn’t know the right end of the sword. Instead they have settled into Star City among the Orkai and are thriving deep within the dungeon and even locating trails for the class to get powerful new abilities. Things in the dungeon are never so simple. Lucian, a Leomatis Shaman is mourning the death of his grandmother before his father decides that Ken would become the perfect obstacle to whet his soft son’s claws. At the same time, the Orkai Arbiters are going scorched earth on some problem that had bubbled up from the dungeon shuffle. As always, the answer is for Ken to grow stronger.

Ken and company find that with the introduction of the Threadspawn, the whole dungeon becomes far less friendly. Even the populace on Earth is spooked. Which is why the UG and Haylon sends Ken and a few others on the press tour. Though, even that can't keep Ken from the action. The Threadspawn invade Earth meanwhile Ken is recruited fully into the demon hierarchy. Now he has to balance loyalties to the UG and the Hierachry while the Threadspawn threat grows ever closer.