I Was Just Doing Overtime Service at the Dungeon, but I Ended up Pretending to Be a Wandering S-Rank Explorer

Hinata Watari is an overworked office drone buried in endless unpaid overtime. Convinced that “moving his body will spark better ideas,” he takes an unusual detour on his way home—into a dungeon that suddenly appeared in the city. There, he vents his pent-up frustration by using monsters as punching bags while casually exploring the labyrinth. But just as he’s basking in the thrill of mowing down weaklings, he stumbles upon a beautiful girl under attack from a fearsome monster! That fateful encounter turns Hinata’s dull, exhausting life upside down. Thus begins a refreshing tale of modern-day dungeon adventures and exhilarating battles!