In the present day, tower dungeons called "Magic Towers" have appeared throughout the world. The main character, Takamichi Yoshito, is a convenience store clerk. The manager yells at him every day, making his life miserable. Yoshito dreams of making a fortune, and soon after the Magic Towers appear. He becomes a "Challenger" of the towers, but he has no savings to invest in weapons or equipment, leaving him completely late to the game. Aiming for a quick turnaround, Yoshito sells his real-life savings and the few items he has in the tower, and buys the "Infinite Revival" skill from a shady merchant. This skill allows him to revive himself within the dungeon. However, "Infinite Revival" had a hidden disadvantage. When reviving, the user is randomly given a "death penalty," a permanent debuff so strong that once it is applied, the user is no longer able to work as an adventurer. Yoshito despairs over the cursed skill, but his situation changes drastically when he obtains the rare skill "Inversion" in a hidden room of the dungeon. The skill "Inversion" reversed the heavy negative effects of Death Penalty's permanent debuff caused by Infinite Revival and turned them all into positive stats...