It's a story about a beautiful boy who lost his mother due a plague (colera, maybe?). An older boy falls in love with him but due circumstances they can't stay together. The boy is kidnapped and ends in an harem where he lives for years. The older boy joins a group of rebels and they assault the harem searching for the story villain (who owns the harem). I don´t remember if there is a happy ending or not.
Any help is greatly appreciated.

I don't know the title, but I am really curious about this one.

I finally found yesterday while I was looking for another manga:
Kinpeibai Kinden Honoo no Kuchizuke.
This mangaka is incredible, I'm going to read all that I can find.