Modern Dungeon Capture Starting with Broken Skills

Four years ago, dungeons inexplicably materialized across the globe, igniting fierce international conflicts over the valuable resources hidden within their depths. Yet this is not a distant fantasy realm—it is modern-day Japan. Mizuki, an ordinary salaryman working in financial securities, has recently been reassigned to a remote rural branch office. However, on his very first day at the new location, he discovers that his workplace has been entirely consumed by one of these mysterious dungeons. Driven by concern for any colleagues who might be trapped inside, he steps into the unknown, only to realize that the interior operates exactly like a video game. During his search through the dungeon's treacherous corridors, Mizuki encounters a fairy on the verge of being roasted alive by a group of goblins. Armed with a newly acquired and enigmatic skill book, he intervenes and rescues her from certain death. With his mundane corporate life abruptly left behind, the former wage slave embarks on an extraordinary adventure. Together with his otherworldly companion and the power of his skill book, Mizuki sets out to conquer the modern dungeons that have overtaken his world.