Rentt meets a beautiful woman in the dungeon! What’s Lorraine gonna say?! After evolving into a thrall, Rentt explores an unmapped part of the dungeon and encounters a mysterious woman. In exchange for his discretion, she gives him a treasure called the Map of Akasha, but before he can learn anything about her, she warps him out of the dungeon. However, meeting her may just be the least of his worries. On his quest to become a Mithril-class adventurer, he must first pass... the Bronze-class Ascension Exam. His new life as an undead adventurer is finally beginning!

It's been ten years since Rentt Faina, a down-on-his luck Bronze-class adventurer, set his eyes on becoming Mithril-class. Unfortunately, Rentt finds himself helpless when confronted by a legendary Dragon in the Labyrinth of the Moon's Reflection... and is summarily eaten. But Rentt has miraculously reawakened... as a Skeleton?!

After Rentt, the undead adventurer, passes his Bronze-class ascension exam for the second time, Sheila becomes suspicious and uncovers his true identity. Despite playing dumb, her sincerity convinces him to tell her everything. Now a Bronze-class adventurer again, Rentt takes a special job from an orphanage for a single bronze coin. But before he can fulfill the dangerous and difficult request, he somehow gains a vampiric servant of the rodent kind. In the fourth volume of this adventure fantasy, can Rentt survive his journey into the poisonous and treacherous Tarasque Swamp?!

After Rentt senses something wrong with his familiar, Edel, he and Lorraine leave Hathara and return to the city of Maalt. There they find the city on fire and crawling with thralls. Rentt finds Edel safe beneath the orphanage and learns through him that a single vampire might be the cause of all the chaos. Just as Rentt goes out to help rid the city of the thralls, he runs into the last person he wants to see in this situation—Gold-class adventurer and vampire hunter Nive Maris!

With the help of Lorraine, Isaac, Laura, and the rest of his companions, Rentt defeats the vampire Shumini after he attacks Maalt. However, in order to take control of the new dungeon, Rentt has to turn Rina into a vampire and make her his familiar. Both Rentt and Rina have leveled up, so Isaac suggests they try out their newfound abilities. He also offers to teach them about a vampire’s most notable skill: Division. Not everything goes as expected though, because while they were supposed to transform into a bat, Rina transforms into a cat and Rentt into a...tree? Meanwhile, people are flocking to Maalt to study the newly formed dungeon. Not to be left out, Rentt and his companions set out on their next adventure to explore the dungeon’s secrets! Fighting powerful monsters, solving countless mysteries, and becoming stronger! The adventures of Rentt, the undead adventurer who aims to become a Mithril-class adventurer, continues in this thrilling ninth volume!

Now that the West has suddenly gained control of powerful new technology, the future is looking grim. Meanwhile, Rain's friend Athly has worries that she's keeping from him. How is everything connected...?