actually he had to do mandatory military service in Taiwan for 2 years. After the war he finished writing the story (no comic) for the Yuyuko's Reimu story and then haven't heard from him since. Probably doing other stuff.
...Okay, joking aside, he is still active it the doujin scene, putting out fanworks on popular stuff in China like TF2, LoL and Touhou.
Yukkuri was just a passing phase Even though he has contributed much on the current collective consciousness, like certain artists here he has moved on to other things.