Fate: Emiya the Host Novel

Shirou discovers the Hosting System at a convenience store entrance—a remarkable ability to designate goals and let the system complete them automatically. His first attempt seems foolproof: "Clear the Holy Grail War and let Miyu obtain happiness."

The system refuses. No Holy Grail War exists in this world.

Undeterred, Shirou tries learning Projection Magecraft, Reinforcement Magecraft, even the Third Magic. Each request is denied. Desperate, he settles for something simpler: "Earn money."

The system accepts, and his body moves without his control. Before he can process what's happening, his arm rises to shatter the convenience store window. Robbery, the system helpfully explains, is the fastest path to wealth.

Panicking, Shirou cancels immediately and demands answers. After forcing the system to comply with legal restrictions, he tries again. This time his body sprints home, grabs a phone, and calls Taiga—the daughter of Fuyuki's most powerful underworld boss—to propose marriage for financial sponsorship.

The system's logic is flawless: a 99.9% success rate according to its analysis. Shirou is horrified.

What kind of system sacrifices common sense for maximum efficiency? As he watches his body betray his intentions again and again, Shirou realizes the Hosting System doesn't understand nuance, morality, or why marrying into the yakuza might create complications he never anticipated.

A harem awaits. Comedy and chaos follow. Recovery seems unlikely.