Yamanaka Suguru always viewed his "first times" as challenges to overcome. But when a girl suddenly confessed to him and became his girlfriend, she introduced him to countless new challenges that he's never known about.

Somewhere among the violent and chaotic grasslands of 12th century Mongolia, lives a boy named Temujin. One day, while on the brink of death, he has a fated encounter with a beautiful and mysterious woman that will affect history. This is the story of a boy who will shake the earth.

A plague-like wind blows across the arid, sandy expanse of a post-apocalyptic Japan. As it sweeps over the living and nonliving alike, rust is all that remains. The cause of this catastrophic state? Mushroom spores. At least, that's what everyone thinks. Enter Akaboshi Bisco. He's known as the "Man-Eating Mushroom," and is a wanted archer whose deadly aim instantly sprouts mushrooms wherever they land. However, in truth, he's a "Mushroom Keeper," committed to spreading fungi to enrich the land and return it to its former state.

A young girl—Chloe La Forêt—is alone and unconscious in the Corpse Forest. Well, it's too bad. At least the monsters will finish her off within a few days. Except this girl gets rescued in the nick of time. And the man who finds her? He's her new boss, Alchemist Kurakazu Rintarou. Chloe has a knack for cleaning and thus becomes his housekeeper. But she quickly reveals another hidden talent of hers—necromancy! Watch as this story of science and fiction unfold under one roof.