Hmmm, I legit forgot about this this guy. I'm guessing he's either in hiding from debt collectors or he's sleeping with the fishes.
There is no substantial evidence to support him working at Compile Heart.
Also, what you're talking about isn't disappearing. If said person disappeared, you wouldn't know they took over an udon shop.
The Udon information on came out after they met up and someone updated their blog.
Before that, to outside fans, this person just mysteriously vanished. People even speculated he might have went to Aokigahara. The same for Mikage, he might just have chose to be out of the spotlight now, but all of his friends and family (not us) knows where he is. They just choose not to go public (and why should they?)
My impression is that Yakuza nowadays want the money (police crackdown and recession hit them hard), rather than your life. Dead people don't pay up, and it is just added cost as they need to dispose of body afterwards.
Even If they done him in, they would want to make him an example, so vanishing doesn't suit their needs also.
If he was on the run, then he shouldn't have cameo on the Compile Heart Video. If he has debtors Compile Heart is the one who will take the heat. It just isn't a very Japanese thing to do.
