Lazy Dungeon Master: Volume 13

I'm Keima Masuda, a Dungeon Master aiming for a life without work. Haku told me about there being a Hell Tournament in the Demon Realm with the reward being the Divine Pajamas, and she even sent me over as an imperial official. She's being so generous I can't help but feel like something's off... And of course, the winner of this year's Hell Tournament suddenly forces me into a fight. "Now then, in accordance to the law, you are now mine." What?! If you lose a duel in the Demon Realm you're the winner's slave? No way! Thus begins my live as a slave. And he's forcing me to train in combat?! This is Volume 13 of my own kind of dungeon story! The demonic hands of forced labor are grabbing for me!

[From J-Novel Club]