Note: This is a review of the Funimation English Dub of Kamisama Kiss.

This anime has only 13 episodes.
Edit: This anime now has a second season, which I have reviewed separately.

Violence / Gore:
There are brief fight scenes in Kamisama Kiss, but little to no blood is shown. Various acts of comedy violence make up this anime.

Nudity / Sexual Content:
There is a scene in which a character talks of taking a girl "by force." One character is found in the red-light-district surrounded by women. A girl falls down and her undies are shown.

Potentially problematic theological themes:
The plot of Kamisama Kiss revolves around a girl who is given magical powers and is referred to thereafter as a "land god." Various other "gods" appear in the anime. Spells and magic are occasionally used (usually in comedic ways).

Other potentially problematic themes:
Characters occasionally drink sake. There is a ritzy party where random people appear tipsy.

*Kamisama Kiss is a lighthearted romantic comedy. If you can imagine it, this anime is like a mix between Inuyasha and Fruits Basket. If you enjoy a good Shoujo anime, Kamisama Kiss is probably right up your alley!

Violence: All fights contain very little blood, if any at all. They are also very short. There is some slapstick violence.

Sex and Nudity: There is no nudity. A character is shown in the red light district with prostitutes. Nothing unsavory is shown. There is a joke about Nanami's chest, and a girl falls over, exposing her underwear (resulting in humiliation). There is a beach episode, too. A male character tries to force Nanami to marry him.

Theological Themes: This series is about Eastern religions. Nanami is made a "land god" and encounters other gods. Familiars and spirits all play a part as well. Time traveling and soul swapping happen magically in an episode.

Problematic Themes: I don't remember any cursing or substances, though I could be wrong.

Overall: This was a fun series. Nanami was an interesting contrast to other female leads in the anime I watched, though I did get frustrated by her lack of progress. I wished she had been able to master her new skills as a god a bit more. The supporting characters are also really enjoyable. Tomoe, the love interest, is an interesting character, even though I don't quite understand what Nanami sees in him romantically.

I do think the romance would have been better as a slow burn, so it did move a bit quickly for me. I've realized that I only really love the enemies to lovers trope when it's slow burn, so that's probably just a me thing.
The concept was nice, and the comedy was lovely, though I could have done without the narrator. I've realized that the comedy was an integral part of why I liked the show.

It's worth a watch for fans of supernatural romance and shoujo. I'd say middle school and up for this one for the occasional suggestive moment. I believe it's rated PG, and I don't remember anything big that would make me think the contrary, though I'd say it's on the more mature end of PG.