One day Hiro, 19 years old stumbles upon a mysterious book in his home library and while reading it finds out that the existence of demon Lord is a mystery in the story. Suddenly a huge earthquake strikes his house and gets reincarnated in that same world as in the book. This is a story about whether he will be able to build relation with some companions in the new world and solve the mysteries about the demon Lord and his own sudden death in real world.