
Yojōhan Shinwa Taikei is an adaptation of Japanese novel by Morimi Tomihiko, created by studio Madhouse and directed by Masaaki Yuasa of Kaiba, Mind Game and Kemonozume fame.
It's also one of the very best anime I've ever seen.
The story is great. The characters are even better. The direction, art style and animation, while they might take a little getting used to, actually complement the story perfectly. The narration style is great as well, though it might be a bit hard on you if you're a slow reader, it's never boring. With few great cast members(Maaya Sakamoto voicing Akashi, Nobuyuki Hiyama as the protagonist's penis(yes, this show is THAT awesome) and Yakushimaru Etsuko singing the ending song) everything comes together to form a great anime.
Now, of course - it doesn't look very much like your mainstream anime, but if that bothers you, then it's not a show for you.
This is an anime that can be different, interesting, and quite artistic, without being pretentious - the story, while a bit complex in execution, is actually pretty simple, and the message is very clear. And the show is really, really fun.
I couldn't recommend it enough.
Sadly, it's licensed by Funimation, so we won't see it on BakaBT anytime soon - but it's not that hard to find it elsewhere, and it's really worth it.