Title: Die
Mangaka: Kaori Yuki (Penname, real name being Yuki Kaori, though I don't see much difference)
This is a psychological manga, not your average love story. Actually, it's only a oneshot, about 15 pages long.
It implies incest, but the most captivating thing about it is how much it makes you think till your head splits apart.
Kaori Yuki has a way with words, and through her drawings, creates a mood more dark and gothic than any you've ever experienced.
A young man reads a letter from his sister, supposedly to have suicided by cutting her wrists as suggested by the swirling mix of crimson liquid and clear water, a knife resting by the side.
He was the one whom his sister first loved, and also the one who compelled her to marry a man the total opposite of him to forget about his existance when she found out his true nature.
Faking her disappearance, he keeps her locked up in the basement turned deathbed where she killed herself.
Before dying she writes him a letter.
The exact same contents of it was also sent to the police station. It is supposedly after her death that the police came and investigated the basement, where they stumble across the young man kissing someone lying on the bed where his sister had supposedly died in.
The kiss stained his lips blood red.
That's all I gathered from overloading my brain trying to make sense of it all.
My guess is that the person is his sister, though how she looked so much like a guy I do not quite understand. Going along with that, I think that the suicide mission failed.
If this makes you think my mind has been twisted beyond recognition, my firm answer is NO. If they had labelled 'incest' under 'genres', I'd probably have given this one a miss.