Gengoroh Tagame is probably the most known and influential Gay Japanese manga artists for almost the past three decades. He recently had a gallery showing in Tokyo at the Vanilla Gallery in the Ginza area. For many people, they only part of the artwork that people get to see is the final image, but if you sign up to Tagame's sketch blog you get to see some behind the scenes process. I find this the most interesting part of creation is the raw image parts, the flaws and stray lines. I didn't get the chance to go to the gallery when he appeared there which i now regret. Hopefully when he has his next appearance in Tokyo i get to meet him.
The video below is a photo collage of his show he had during tokyo Gay Pride weekend in Tokyo this past August.
Here is a video he did on the process to make a comic cover.