Aki Sora

It's banned in Japan. The first and third manga volumes will never be reprinted, thanks to Tokyo Metropolitan Ordinance Regarding the Healthy Development of Youths, aka. Bill 156.

It's still out there, though, and one of the most notorious incest anime/manga. (It was released alongside Yosuga no Sora, though, which is an even more famous incest anime/manga. Both anime adaptations even shared a director and some voice actresses. Aki Sora is by far the more censorable of the two, though.)

Sora is male, but also the most timid, blushing maiden in his family. He does all the cooking and housework. His older sister Aki takes the lead in their relationship, i.e. has baths with him and masturbates him. His twin sister Nami is aggressive, hostile and boyish. They have a mother (who might also commit incest with Sora one day, but doesn't in these episodes) and no sign of a father. Also, Nami's best friend, Kana, is timidly in love with Sora and hasn't realised that she has a lesbian admirer in Nami.

Are these OVAs hentai? Maybe, maybe not... but you'd have to give reasons if you decided "no". We never actually see a penis in action, but we see pretty much everything else.

It is, though, far better written and animated than the vast majority of hentai. When I finished the third episode, I went off to find the manga's last chapter because I needed to see what eventually happened in the story. Ep.1 is straightforward, if depraved. Aki seduces Sora. Simple as that. He's reluctant and he thinks it's wrong, but he's also always secretly fancied her. There's nothing too surprising in the plot, bar the terrifying moment when Nami's coming home and you're convinced she's going to catch them at it.

In ep.2, Aki and Sora are still doing it like rabbits and aren't showing enough caution about it. (They're not even using contraception, as far as I can tell. That's alarming too.) Aki wanks off Sora in the kitchen when anyone might have come in, then kisses him on the lips at school. On the stairs. Once she even fellates him while Nami's in the same room, albeit asleep on the sofa. That was hair-raising. Aki has superhuman "get dressed in a hurry" skills, admittedly, but even so does she secretly want to get caught?

Then there's the Nami-Kana-Sora triangle. An increasingly bad-tempered Nami is pushing Sora into going out with Kana, because that's what Kana wants and she loves her. Nami's also, though, masturbating to pictures of Kana.

Then, in ep.3, things get twisted. Pretty much everyone has sex, including one combination with physiological impossibilities that's actually Nami's wet dream. The episode ends with Kana happy (but for how long?), Aki still jumping Sora's bones at every opportunity and Nami having done something extremely surprising because she's dangerously messed up. (At one point, she goes dark and psycho with a pair of scissors.) The end credits roll with our heroes apparently happy, but teetering in an unstable four-way love quadrilateral that's almost certainly going to blow up in their faces and might end in blood. I can see two stable endings and any number of tragic ones. There's the "happy but wrong" ending in which Nami successfully woos Kana and so everyone's more or less got what they wanted. There's the "unhappy but legal" ending in which Kana wins the race to get Sora. And you don't need me to speculate about tragic endings.

You can see why I went looking for the manga.

SPOILERS

"Happy but wrong" is the winner.

This isn't a major work. It's only three anime episodes and thirty manga chapters. Getting banned only a year after the manga was finished has made it comparatively obscure. It's nowhere near as good as Yosuga no Sora, which I'd genuinely recommend. It does, though, have its own kind of power.