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

I'm a former hero returning from another world, but I was involved in a death game , A former Hero returning from another world gets involved in a Death 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.