Aoi Bungaku has a very, very loose adaptation of No Longer Human. I was disappointed by that.
On top of that, Oba Yozo gets laid on the reg, is attractive and kind as well as being socially competent, the complete opposite of a /tc/ user. His flaws (which is where the /so/ stuff starts to come in) came from not recognizing his innate goodness and having some kind of anxiety disorder and a predilection for suicide. It's literally the fulcrum of the story. I've read it at least 5 times, it might be my favorite book of all time. (Real spoilers ahead don't look until you've finished/don't care.)
Osamu Dazai actually ended up throwing himself into a canal with a woman, similar to Oba Yozo, he romanticized the idea of a lovers suicide. No Longer Human is the result of some genuinely dark urges. It starts to seem like a seriously fucked up book when you read it with that factoid in mind.