That's interesting. I never doubted that PC Cocoron existed in some form. The weird thing is that over the course of the PCE's life, PC Cocoron was announced a number of times. It had at least two concrete dates that I can remember. Of course each time the dates slipped into the unknown.
I'll have to go back to my old mags and do some digging. I never did notice anything about why the game never came out, but it seemed to me that there had to have been some retail copies made. I believe the game was even reviewed by at least one PCE mag. Not only that, there was a similar situation with Imperial Force. Not sure if any specific dates were mentioned for that game, but it was basically delayed forever. Both games were done by the same team (Sur de wave ??) and it turned out that they never even officially released anything on the PCE.
It's a shame. Both games looked interesting to me. But I read on a webpage somewhere that PC Cocoron, despite it's colorful gfx, had ok gameplay. I don't remember the link now, but I wonder if the webpage was by that Yuki person.