Theoretical Weapons Exist in the Fantasy Continent

The future world traveled to the fantasy world and tried to pick up one of the theoretical swords he had used for the 5000th time, but was sucked into the fantasy land by a wooden door. In order to protect himself and return to his original world, the protagonist has to collect information about this world bit by bit and hide the power from the future... This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.