Yuji Sano was a normal guy working a soul-sucking nine-to-five job when he suddenly found himself transported to a fantasy world where he restarted his life as a Monster Tamer. After befriending the Slimes, Yuji is quickly able to gain a second character class, ranking up his stats and learning new skills as he encounters one surprise after another.

While trying to find more information regarding the cursed tree found on Evildominus Island, Yuji stumbles on the small town of Declen. After discovering the local Adventurer's Guild, he is tasked with a quest to clear out an infestation of wraiths that haunt the nearby forest. In the midst of the quest, he meets a wraith who differs from the other inhumane spirits, though it remains unclear if she is a friendly ally or a dangerous foe. What secrets lie in the grudge she carries from beyond the grave?