I’m a former hero returning from another world, but I was involved in a death game

Story:

A former Hero returning from another world gets involved in a Death Game. Ise Kaito departs for a school trip with his classmates. He enjoyed his daily life as an ordinary high school student, but suddenly he was caught up on the stage of a death game where a man in military uniform ruled the place. The weak will die, the strong will be the winner … But they were unaware. That one of the students is the former strongest Hero, who returned from another world.