Comic Master J

In the manga publication industry, there is a legend:

If you leave a message on a bulletin board in the train station at Shibuya, you can obtain the services of a certain man ... No, not City H*nter. Comic Master J -- an assistant mangaka who can instantly complete any publication manuscript in any art style for the price of 5 million Yen. However, he refuses to work on manga without a "soul."

But what is J's true identity? Why does he wear an overcoat lined with pens and rulers? Is his real name B*ack Jack? And for what reason does a man of such artistic talent choose to live in the shadows of the industry, rather than working on a manga of his own creation?
J's past and his relationship with the mysterious organization "CLUB" may tie in with a secret war for the fate of human culture as we know it ...