Gamer Kazuma dies in a freak accident, and is met in the afterlife by a crass goddess, Aqua.

It's great for Kazuma that he brought Aqua along with him, but unlike in a game world, much is missing from his adventurer's lifestyle. No money, no equipment, and even fighting the lowest ranking monsters is a hard-fought battle. That's when they decide to recruit new party members.

A low-grade goddess turned arch priest who works hard to acquire party trick skills, a disappointing arch wizard who can only unleash explosion magic once per day, and Kazuma himself, whose only redeeming quality is his good luck. Kazuma despairs over the completely useless party that's been formed.

All of the weak monsters have gone into hiding since a leader of the devil king's army has settled in near town. Kazuma, who had been focusing on improving his skills, is stuck at a standstill. With nothing else to do, Kazuma tags along with Megumin's training, which consists of unleashing explosion magic into an abandoned castle.

Wanting to earn some money despite only hard quests being available, Aqua takes on a request to purify a lake filled with alligator monsters, with the others putting her in a cage to keep her safe.

Annoyed that Megumin had still been using his castle for explosion practice, Verdia, after proving easily susceptible to Aqua's purification magic, summons an undead army which is quickly defeated by Megumin's explosion magic.

Needing money to pay off his debts despite the freezing weather, Kazuma and his party takes on a quest to kill Snow Sprites.

Kazuma and Aqua visit a magic shop run by a kind-hearted lich named Wiz, who reveals herself to be one of the Devil King's generals in charge of protecting a barrier surrounding the Devil King's castle.

Kazuma and his adventure friends Keith and Dust go to a shop run by succubi who provide male adventurers with much needed relief by giving them erotic dreams.

With their members being perfectly suited for the job, Kazuma's party, along with Wiz, are chosen to lead an attack against the Destroyer.