Miss Kobayashi's Dragon Maid

Kobayashi saved an nigh omnipotent (by the standards of our world) dragon named Tooru. Now Tooru is Kobayashi's enthusiastic maid. Anime to be released in Jan 2017.

Tropes used in Miss Kobayashi's Dragon Maid include:

90% of Your Brain: Tooru comes to the conclusion this is true in chapter 18. She's just easily impressed with illusions because she doesn't detect "magic" (this conflicts with Tooru's suspicions of how cars work in chapter 7, as cars wouldn't give off magic).
Department of Redundancy Department:In Chapter 30

They'll get a free tour around Gehenna, Jahannam, Hellheim, and finally, the Lake of Fire.

—Tooru

Faking the Dead: Almost. In chapter 7 we find out that Tooru is believed by most people to be dead and Tooru felt it was more convient to keep her survival a secret.
Happiness in Slavery: Tooru is usually very happy with where her life is right now. And if she wasn't, it's not like anyone from our world could stop her from taking her freedom. And it's not like anyone from outside our world is interested in forcing Tooru to remain in her current situation. And while one could make the case that "maid" isn't a subset of, or synonym for the word, "slave", it's not like Tooru has the most accurate understanding of what the word "maid" means (as shown in chapter 17).
I Owe You My Life: Kobayashi saved Tooru. Tooru "having nowhere to go" anyways might have played a role in taking this course of action. Kobayashi standing up to Tooru's dad in chapter 20 certainly didn't take away from this.
Mayfly-December Romance: Between Kobayashi and Tooru. It's probably one sided though. Tooru can do a lot, but she can't make Kobayashi live forever.
Sex Slave: In chapter 17, Tooru claims that she is a maid, which means a sex slave. Kobayashi, of course, tells Tooru that's not what a maid is.