"Please, help us, Demon Lord!"

It's a typical hero summoning often found in 'isekai' stories, but instead of humans, he's surrounded by demons!?

What's the point of summoning an old man like this?!

On top of that, once they realize he's just a human and not a demon, they start making all sorts of demands: "Kill him!" "Make him a test subject!"

Even an old man has his limits, you rotten bastards!

He had absolutely no intention of helping demons, but after a series of circumstances, he ends up siding with them and heading into war against humanity...

*Also posted on other sites.