"What Doesn't Kill You" by Stark_Black

I love a fic that takes a topic I don’t normally read, just for lack of personal interest, and draws me in to the point of having re-read it five times. It’s BDSM culture, so there’s explicit content of the sexual and harmful side, so be warned, but the author does an amazing job of education and having characters give consent (when they can—Kakashi and Iruka are under cover so there are a few dubcon moments).

Fic on AO3: https://archiveofourown.org/works/5338175/chapters/12325994