phenomen a book

Johannes Aarvold is a normal student who yearns for knowledge on every medium possible. He is having the time of his life when he figured out that the girl she loves also loved him. But because of an Unusual Blue Book that he borrowed from the Library, he was transported to a different world called Veneofel. But the moment he was transported in Veneofel, he fell straight towards the castle of the Final Boss, The Demon King!