@crokto
Sacrificing an innocent to save yourself is an evil act, full fucking stop. Its not made "good" because its saving your own ass. ESPECIALLY not once you've granted them sanctuary already.
As for why the implication of rape...well, they were gonna feed her to a dragon, might as well fuck her first. Once you start down that path, its real easy to say "fuck it!" and keep going.
Besides, as a trope its hardly limited to the japanese. They tend to use it a bit more liberally, and explicitly, but its not like American or European stories are pure as the driven snow in this regard.
I admit that the overuse has severely depleted the impact it has on the reader. But the fact that you're triggered suggests that it does carry some weight still.