Natsuki Subaru steps out of a convenience store and into another world, with no cheat powers and no hero's welcome. A silver-haired girl named Emilia saves him from a bad first night, and he resolves to repay her. Then he dies, and wakes hours earlier as the only person who remembers. Tappei Nagatsuki's isekai turns that loop into a grinding test, where every failure resets the clock and every reset exacts a price. The fantasy trappings sit over a story about panic, obsession, and the cost of trying again. Studio White Fox pairs bright design with genuine cruelty.