In a world on the verge of a great disaster, heroes who, with the help of a device called HxEros, use the power of Ecchi (H) and erotic power (Ero) to save the planet from libido-devouring monsters!

Five years ago, an unknown type of alien called "Censor Bugs" invaded the Earth. They plunder "H energy" in an attempt to evolve their own race and make mankind extinct. To save the Earth from this alien threat, high school boy Retto Enjo joins the "HxEros" team, partnering with four gorgeous high school girls; one of whom is his childhood friend Kirara Hoshino. However, it turns out that Kirara has changed her personality a lot which leads to an estrangement between the two childhood friends.