In "Misfit Demon King Academy", Sasha Necron makes a bet with the demon king regarding one of the competitions. She says that if she wins, "Then I own you."
In "Didn't I Say to Make My Abilities Average", Mile agrees that if her team loses to all of Arledy's minions, the noble Arledy would own miles.
I've seen this trope in a number of other anime as well, "owning" someone as a result of a bet. Does anything like that every happen in real life? Is there historical precedent that it stems from? In the US, that concept would be an absolute taboo as it would connotate slavery which is still a recent blight in our nation's history.