In ancient China, women bind their feet for cosmetic reasons, resulting in them not able to walk without help and walking in a shuffling gait.
Possibly this can be modified such that people do it for less stupid reasons.
Disclaimer: This is NOT a racist remark since I'm Chinese myself and hence entitled to freely judge Chinese customs. NOT sexist either since I'm female as well.
This really comes from an ancient Chinese novel. Imagine during the PCs' travels, they come to a place where the gender roles are completely reversed. What adventures will the PCs encounter in such a place?
A sentiment weapon that is very impressionable in terms of what is right and wrong, akin to a child. Currently, being ownerless, it is not very powerful. However, once it has found an owner, it can provide significant boosts to the wielder in an area or areas the wielder most desire. What adventures will this sentiment weapon go through? How will it develop itself in terms of power and personality?
King dresses as a commoner occasionaly and makes his way through the town. It is an unknown occurance so nobody expects it. This time he is mistaken for a thief and jailed. Not wanted to reveal himself, and always curious for the experience, he allows himself to be arrested. PCs also get arrested for something, probably guilty but pay a fine. How they act towards the 'king' could greatly change how their first meeting will be as the players always meet the king at some point.