Magical Equipment Sealed Book

As an ordinary courier, I accidentally delivered a strange courier one day. Feng Chun felt a little tired, both physically and mentally. Not only was he forced into a dangerous world, why did everyone else have serious demonic tools to fight with, but he only had... A book. ? This is a story about how even though he looked confused and even wanted to cry, he had to grit his teeth and try to live with a smile.