Contract With Demon

Issei Iwatani, was going on a school trip with twenty other students and a female teacher. But the suspicious bus took them to another world where people and royals were waiting for their arrival. They are known as heroes and they are to fight against the monsters. But Issei was cast aside because of his low-level spirit beast, turned into a tool for a greedy higher up to play around with. Later he found out the spirit beast he summoned was not a spirit beast, rather than a demonic system with feelings who is willing to make a contract with Issei.