Game loving shut-in Kazuma Sato's life as a young schoolboy in Japan abruptly comes to an early end...or at least it was supposed to. When he opens his eyes, though, he sees a beautiful goddess that offers him a once in an after-lifetime chance to be reborn in a parallel world. The catch is that the world is violent and threatened by a growing evil! Fortunately, he can choose any one thing to bring with him. So he chooses the goddess, Aqua! And so his adventure with his gorgeous companion begins.

After Kazuma and crew's less-than-relaxing vacation, Yunyun burst onto the scene with shocking news—the Crimson Magic Clan is in danger, and she wants to bear his children to save it! Kazuma returns with her to the village, but the situation isn't quite what he expected...

In Orario, fearless adventurers band together in search of fame and fortune within the monstrous underground labyrinth known as Dungeon. But while riches and renown are incentive enough for most, Bell Cranel, would-be hero extraordinaire, has bigger plans. He wants to pick up girls. Is it wrong to face the perils of Dungeon alone, in a single-member guild blessed by a failed goddess? Maybe. Is it wrong to dream of playing hero to hapless maidens in Dungeon? Maybe not.

Beautiful and brilliant sorcerer girls just can't have nice things, huh? All I wanted to do was swipe a little bit of bandit treasure. Now suddenly I'm being chased around by icky trolls, nasty demons, mean mummies, and brooding golem bad boys. And for what? A tiny little artifact that can bring about the end of the world? Hah! I'll show them there's a reason you don't cross Lina Inverse...

Kicked out by his family and wandering the streets, an unemployed 34-year-old shut-in thinks he’s hit rock-bottom—just as he’s hit and killed by a speeding truck! Awakening to find himself reborn as an infant in a world of swords and sorcery, but with the memories of his first life intact, Rudeus Greyrat is determined not to repeat his past mistakes. He’s going to make the most of this reincarnation as he sets off on the adventure of a second lifetime!