Murder in a closed room, disappearance, impossible crime, floating corpse, instant beheading... The world we live in is full of mysteries, like fog covering our eyes, or gauze covering the truth. A genius girl who "will die of old age if she doesn't think" relies on her extraordinary IQ, uses the "power of logic" as a weapon, and bets her life to deal with a series of bizarre and bizarre events with a cute science tyrant boy, breaking unheard-of criminal methods and solving all kinds of mysteries left in the world. Reasoning... just to survive.