Nana to Kaoru is a seinen manga, which is about the relationship between high schoolers Nana, who is an outstanding student, and her long-time neighbor Kaoru, who has a (unhealthy?) interest in bondage and other forms of SM play.
The message conveyed by most manga, is no normal girl is or should be interested in taking part in a boy's fetish. Girls are prudish; boys are hyper-sexual.
But in the case of my favorite adult manga artist, Amadume Ryuta, who I discovered back in the days I started collecting adult manga, his female characters aren't just "strong" in the sense of most men's comics, but have an innate curiosity for sex. Or at the very least, a lack of prudishness, which is what's usually employed for comedic effect, but is both cheap and tiring.
In Nana to Kaoru, most of the comedy is light-hearted situational comedy. Which balances the more serious aspects, of sexual exploration. With all the ropes tied tight through the thighs and around the breasts, outdoor urination, etc. it's pretty strong stuff for 2nd year high school kids to be playing around with. It's not entirely credulous but anything is allowed under the guise of comedy.
And it also seems to contain the beginnings of a love story: Kaoru is interested in SM play and not sex and isn't in love with Nana. Nana isn't interested in sex either, but finds SM play relaxing. They are just long-time friends, it seems. And might they go beyond just SM into sex? Or will they find themselves in love? Or both?
There are two things I'm looking forward to in volume 3: How will Amadume "step-up" (as it says on the cover) the SM? And will Kaoru and Nana ever develop love interest?