One day, Maho, a high school girl who absolutely loves home centers, was suddenly transported to another world—along with an entire home improvement store! She found herself in the deepest part of the legendary "Melquodia Grand Labyrinth", an unexplored dungeon known as the toughest in the world. There, she met Fiona, a lone adventurer who had been stranded by a trap. To escape, they must defeat the dungeon's strongest boss, the Red Dragon—an impossible feat for any normal person. But Maho isn't worried at all. "We'll be fine! After all, we have unlimited supplies from the store!" Thus begins a home-center-powered reverse dungeon conquest! With an arsenal of everyday tools and modern survival goods, Maho and Fiona turn the deadliest dungeon into their own playground!