Thirteen years after his childhood friend Miriko vanished down an old well, Takashi is reunited with her under extraordinary circumstances. In the years she was missing, Miriko crossed into an underground world and conquered five kingdoms there, becoming a ruthless queen who commands a grotesque monster army. Now she has returned to Earth with a single-minded goal: to conquer the world for Takashi, fulfill a childhood promise to make him king, and marry him herself. Takashi, a passive and ordinary young man, has no desire for world domination and must find a way to stop Miriko’s reckless rampage before it destroys everything.

The story unfolds as a high-energy, sometimes darkly comedic catastrophe driven by selfish, impulsive characters and the author’s bizarre invention. Miriko’s straightforward approach to conquest—proclaiming her intentions to the public, summoning monsters, and battering through any opposition—quickly draws the attention of local authorities, then the Japanese prime minister, and eventually the United States. Despite her overwhelming power, the conflict never escalates to a full global takeover. Humiliating defeats, absurd political negotiations, and Takashi’s constant attempts to reason with her keep the plot in a state of chaotic stalemate.

As the narrative progresses, the focus shifts from straightforward invasion to a broader threat posed by a mad scientist who seeks to exploit the chaos to build his own empire. The series concludes when Takashi and Miriko, despite their differences, unite to stop this new enemy. Rather than achieving world conquest, the story ends with the mad scientist’s scheme thwarted, and the damage confined largely to Japan. The manga is a destructive comedy that revels in the absurdity of a normal boy trying to manage a spoiled, superpowered childhood friend who genuinely believes she is doing everything for his sake.