My Status as an Assassin Obviously Exceeds the Brave's

Story:

One day, an ordinary group of sophomore students suddenly moves to a parallel world, where they are met by the king of one of the local states. He asks the students to help in the war with the terrifying Lord of Demons, who started a war between the four continents. Unexpectedly, everybody will know that from now on they have unique abilities and personal specialization. Akira, a lonely boy who has always stayed away from people, finds that his level of ability is much higher than that of his other classmates combined, and in fact he is… a professional killer. Having hidden the truth from his comrades, Akira starts his own game and soon discovers the terrible truth about the royal family. In his journey he will meet a pretty elven girl and go to the guild of adventurers. What adventures await a murderer who does not want to become a hero?