How about an action story with an agent who is a master of disguise only he gets captured - its hard to run in high heels - under tough questioning his captors discover he is a male in disguise and they offer him two choices death by firing squad or perm transformation. he decides on the latter thinking he will escape or they wont go through with it. As time passes he begins to regret that he didnt chose the the firing squad.
I think the bad guys would need a good reason for wanting to feminize him, otherwise it would seem pretty silly. This is somewhat similar to an idea I had (or an idea I stole subconsciously from a story I no longer remember reading).
Dystopian near-future, two warring factions. The main character and maybe 2 or 3 buddies are recently captured P.O.W.s who are given the choice: 1) forced labor in extremely hazardous conditions with a 99% mortality rate within the first few months, or 2) some sort of futuristic feminization and training as concubines to be given away as rewards to successful military officers.
At least 1 or 2 of the buddies would be badass macho types who'd insist that they all take their chances as laborers, but the MC of course and maybe one other would be too afraid of dying and thus reluctantly go the concubine route. Or maybe they all start as laborers but after one of them dies horrifically the MC reaches a breaking point and begs for feminization. Then ideally all the friends who survived would meet up again toward the end so they can all see what became of the others. Or maybe one of the macho guys escapes and tries to rescue the MC and they fall in love and live happily ever after. Or the MC refuses to be rescued because living a life of luxury as a sex toy for a rich officer is way better than the life of war and poverty they came from.