Well, it seems to be a revenge manga, alright.
The hero seems to be your textbook naive character who decides he wants peace, as is tradition.
He is friends with many girls with back issues, so far respecting the tradition.
He fights the demon queen, who also have back problems, and defeat her only to be betrayed in the end. He probably couldn't foresee such development due to his d*ck being compromised by his closest friend...
Yeah, i will need chapter 2 to see whether this series will be good or not, so far it is just another revenge manga, which is normal..since there's only 1 chapter...