Story

Saya's family, the Saotome family, is a prominent noble house, and Saya is the heiress and only daughter.

Saya was born with a misfortune-prone constitution, where bad luck follows her at every turn. Injuries, illnesses, and accidents—all sorts of misfortune befall only Saya. However, a strange phenomenon occurred: when the old nanny who had watched over her since birth was nearby, the misfortune mysteriously ceased to happen.

When Saya was five, that nanny passed away, and soon after, misfortune suddenly struck again. Frightened, Saya ran out of the house, only for a truck with a sleeping driver to barrel toward her. Right before her eyes, a five-year-old Guest stood in the way with arms spread wide; the truck swerved and crashed into a telephone pole. Seeing this, Saya's heart was stolen... "My Knight," she thought, and she began to love Guest with single-minded devotion. From then on, as long as she was near Guest, any misfortune that occurred would somehow resolve itself automatically. If someone tried to kidnap her, the culprit would trip and knock themselves out against a wall; if someone tried to harass her, an object would fall from above and hit them on the head; even if she had a fever so high it was life-threatening, as long as he was there, it would end as if nothing had happened. Even if she was injured, she actually wasn't. Even if told her bone was broken, if he was there, it would turn out it wasn't. He possessed an incredible power (ability). Exclusive to Saya.

From that point on, the Saotome family began to rely on Guest to take care of Saya. An attendant and bodyguard.

Eleven years have passed, and she is now a high school junior. Saya attends an elite girls' academy. In her class, she is popular and a central figure.

And for some reason, she has become a high school detective!!