I'm trying to look for this Yaoi oneshot manga that I read a while ago but can't remember the name but I remember all the details.

These categories seem to fit the yaoi manga:

-yaoi
-adult
-smut
-yandere
-humiliation
-mature
-forced
-horror
-tragedy

So it starts off with these 2 brothers and an assistant. The older brother is a doctor If i remember correctly, and he's hugging his younger brother and vice verse. The younger brother drink some kinda memory erasing medication that's prescribed by the older brother and then goes too sleep. The younger bother has a fiance, but she went missing a while ago which put the younger brother into depression. The assistant is concern and confronts the older brother about the meds saying if its ok to give the younger brother these meds. They argue a bit and the assistant gives up. Then the phone rings and before the two could pick up the phone you hear the voice mail, and its by the mother of his younger brother's fiance. She's yells and tells the older brother to pick up the phone saying "I know you killed my daughter!," and more yelling. But before the voice recording finishes the older brother hangs up the phone. The assistant heard everything and tried to get away but is stopped by the older brother. After some pleading and saying he (the assistant) won't tell anyone. The older brother pushes the assistant down and restrains him with a belt or something. First the older brother gives the assistant this aphrodisiac pill drug and then proceeds to rape him. After awhile the drug kicks in and well ya know! XD After that it assistant becomes addicted but has a ropes tied around his penis but can't ejaculate. The older brothers says something like "if you become mine ill let you cum." The assistant agrees, then scene changes to him talking to this younger brother. The older brother is fondly talking to his younger brother and then says he has to go somewhere, and the younger brother is pouting saying the older brother is anyways going somewhere around this time. Scene changes again and his in this prison cell like basement. The older brother opens a door, and you see the assistant in a straitjacket leaning against the wall. And the older brother talks a bit and saying he has a present and drops off a decapitated head. The assistant cries and calls out the name of the decapitated head. And it ends with the older brother saying, "you belong to me now".

Some visual descriptions. The older brother has this very typical manga doctor hair cut and wears glasses. The younger brother has smooth neck length hair and has facial hair on his chin. And the assistance had something like a buzz cut but longer.

Also this isn't the manga I'm talking about, but It's similar-ish? I remember I found this manga around the same time as the one I'm mentioning. It's kinda like: The Passion of Aragaki Shuya. Maybe?

Please help me find this manga, and thank you for taking your time to read my post.

It's called: D no Satsujinsha – Shoshitsu dj

It's from some sort of doujinshi, apparently, but I've never found the source material.

OMG YES! Thank you!

I found some info on the doujinshi from Myreadingmanga.org

Apparently the dj is based off a play called "Shoshitsu that was performed in 2005 by the group Nylon 100℃." written by some new Japanese drama world artist calling himself Keralino Sandorovich.

The play Shoshitsu (Disappearance) by Nylon 100 degree consist of 6 actors, (4 male and 2 female).

"Set in the near future in an unspecified foreign country, this play focuses on two orphan brothers living humdrum lives in a town that has been menaced by chemical pollution. One day the younger brother loses all his memory as his circuits switch off because, it turns out, he is in fact an android. And he’s not the only one"

"Set in the near future after the most recent war, two brothers aged 39 and 35 live humbly in a dystopian town somewhere on Earth. It is Christmas, and the elder brother devises a plan to force his introverted younger brother to make a move on the girl he is in love with. Through casual conversations on topics such as the failure of the second moon station, the green smoke rising from burning stations, the deformed crows, bronze statues melted into weird shapes by the heat of explosions, air raids, terrorists, and so forth, we gradually learn of a distressing “disappearance."