One day Mitsuha falls off a cliff and is tranported to a medievel Europe type world! After a near death encounter with a pack of wolves, she then realizes that she's able to transport between two worlds- this one and her own. Taking advantage of this ability, Mitsuha decides to live in both worlds and calculates that she'll need 80,000 gold coins to be able to retire! Mitsuha now has to come up with different ways to collect her gold coins!

With one success after another, and connections to nobles and royals alike, things are going well for Mitsuha's General Store. That is, until a neighboring kingdom launches a surprise invasion! At first, Mitsuha intends to stay out of the fray, but after being summoned to a war council meeting, a particular incident ignites a fire inside her. Will the Lightning Archpriestess be able to lead her adoptive kingdom to victory against their attackers?