In Japan's wiki entry, it said that he hates cockroaches to the extent where he would cry over them? Where does it mention that? O_o
Sorry for the late replay, I didn't have time to research this earlier.
Apparently it's from the oooold 2006 October blog entry, which I thankfully have a back up of. I asked one of the translators to go over it, and this is the full thing:
>>Hello, I really enjoy your work. There was a scene with Japan staring at a cat. Is Japan a cat person?
Japan likes both cats and dogs. (*´∀｀*) He also likes watching birds.
He gets excited when he sees horsetail shoots and swallow nests which symbolize the arrival of spring.
He also likes to listen to the sound of insects. But he hates centipedes and cockroaches so much that he'd be in tears when he sees them.
The old blog entries are here, but they're still mostly in Japanese: http://www.hetarchive.net/scanlations/oldblog/index.php