Everyone with a dead-end job sometimes wishes for something to come swallow up their workplace... and that's exactly what happens to Mizuki Ryosuke. Monster-infested dungeons have appeared all over the world, but he's saved from his collapsing office by a swordswoman and a pixie. Along the way, Mizuki picks up an item that allows him to pass overpowered skills to other people - and before he realises it, Mizuki is in high demand himself!

Is this another world? No, it's modern-day Japan!Four years have passed since dungeons suddenly appeared all over the world, sparking conflict over the resources hidden within. Then one fateful day, a financial securities salaryman named Mizuki, who was relegated to an office branch in the countryside, arrives at his new workplace to find it transformed into one of those very dungeons. Entering to search for anyone who might be stuck inside, Mizuki realizes the dungeon is straight out of a video game!During his search, he comes across a fairy and, using his new mysterious skill book, saves her from being roasted alive by goblins.The former wage slave’s adventure begins now, as he sets out to clear modern dungeons with his skill book and his partner from another world!

Using his mysterious Skillbook ability, former salaryman Mizuki and his partner, a fairy named Kessie, live to fight another day. They’ve both had enough of the dangerous exploring, but a public servant named Tachibana offers Mizuki an official government Dungeon Advisor position.Reluctantly, Mizuki accepts, but the other adventurers he meets despise him for his lack of experience. He heads into a dungeon for some training, but his party encounters a boss slime that has disguised itself as a cave! Against a such a strong foe, Mizuki and his party will have to use their quick wit and their skillbook strategies, but will they be able to save the day?

Everyone with a dead-end job sometimes wishes for something to come swallow up their workplace... and that's exactly what happens to Mizuki Ryosuke. Monster-infested dungeons have appeared all over the world, but he's saved from his collapsing office by a swordswoman and a pixie. Along the way, Mizuki picks up an item that allows him to pass overpowered skills to other people - and before he realises it, Mizuki is in high demand himself!

Is this another world? No, it's modern-day Japan!Four years have passed since dungeons suddenly appeared all over the world, sparking conflict over the resources hidden within. Then one fateful day, a financial securities salaryman named Mizuki, who was relegated to an office branch in the countryside, arrives at his new workplace to find it transformed into one of those very dungeons. Entering to search for anyone who might be stuck inside, Mizuki realizes the dungeon is straight out of a video game!During his search, he comes across a fairy and, using his new mysterious skill book, saves her from being roasted alive by goblins.The former wage slave’s adventure begins now, as he sets out to clear modern dungeons with his skill book and his partner from another world!

Using his mysterious Skillbook ability, former salaryman Mizuki and his partner, a fairy named Kessie, live to fight another day. They’ve both had enough of the dangerous exploring, but a public servant named Tachibana offers Mizuki an official government Dungeon Advisor position.Reluctantly, Mizuki accepts, but the other adventurers he meets despise him for his lack of experience. He heads into a dungeon for some training, but his party encounters a boss slime that has disguised itself as a cave! Against a such a strong foe, Mizuki and his party will have to use their quick wit and their skillbook strategies, but will they be able to save the day?