An unemployed, middle-aged NEET named Yasuhiko Akizuki spends his days as a shut-in, wandering the internet until he stumbles upon a mysterious RPG character creation screen. Intrigued by a set of unusual skills labeled as erotic, he selects them and begins the game. However, instead of playing, he loses consciousness and awakens in a pure white void before a clumsy, glasses-wearing goddess. She informs him that he has been accidentally summoned to another world as a hero. Unable to return him to his original body, which has already been customized for this transfer, she sends him off to a fantasy kingdom.

Akizuki arrives in this new world as a full-grown, unremarkable-looking middle-aged man, completely naked. He quickly learns he is what the locals derisively call a mass-produced hero, one of many summoned individuals who are given minimal support, almost no money, and are left to fend for themselves. Upon his arrival, he is mocked by local adventurers and even physically assaulted by a headstrong, sword-wielding schoolgirl named Serina Shiraishi, who was also summoned as a hero. Facing the harsh realities of this classic fantasy world, Akizuki decides to weaponize his unique set of erotic skills to not only survive but to grow powerful and prosper. The story follows this unlikely, lecherous hero as he uses his unconventional abilities, navigates dungeons, builds a party, and aims to eventually save the world, all while dealing with the comedic and explicit consequences of his skill choices.

The main character is Yasuhiko Akizuki, an older, bearded man with a gamer's knowledge and a pragmatic, if somewhat pathetic, personality. He is joined by Serina Shiraishi, a hot-headed young woman who wields a sword and initially has a violent relationship with him. Another key companion is Mina, a beastkin girl with animal ears and a tail. The supporting cast includes other summoned heroes like the archer Shinya Sakazaki, the magic user Edwin Jooton, the young swordsman Kage Takayama, and the doctor Hiroshi Kojima, as well as the clumsy goddess who oversees the heroes and royalty such as Prince Albert Grand Vania. Early narrative arcs focus on Akizuki's humiliating introduction to the world, his struggle against the stigma of being a mass-produced hero, forming an adventurer party, and the gradual mastery of his erotic skills to overcome challenges that traditional combat cannot. Later developments, according to reader accounts, involve the protagonist acquiring a harem of companions, with the plot expanding into more complex dungeon crawling and political conflicts, though some reviews suggest the story quality diminishes after the initial volumes.