肉 (にく) – the character for meat. It always reminds me of a ribcage or a little rack of lamb or something. Maybe a bizarro chicken tulip.
The concept of meat in Japan is slightly different from that in the U.S. Here, to the great collective unhappiness of all vegetarian expats, it refers to mammal meat – beef and pork, mostly – and not the flesh of living things in general (at least when talking about food). So, saying you don’t eat meat (肉は、食べません) won’t always earn you a meal that meets (har har) your dietary restrictions, especially if you take into account broths and pastes and flakes (many of which are fish-based).
(On a side note, I once knew a “vegetarian” who ate ramen and just gave away the チャーシュー on top – what a joke! Ramen broth is, more or less, pig rendered into a delicious liquid form.)
When I was a CIR on JET, I was forced to explain strict vegetarianism to Japanese people for expats on a number of occasions. (Including one Lithuanian artist who wouldn’t eat mushrooms for some reason. His English was really bad, but from what I could gather, spores are little people.) I found the best way to explain it is to say that you don’t eat 動物 (どうぶつ, doubutsu) – animals in general. But even that was not general enough sometimes, so I would always bastardize the pronunciation to 動き物 (うごきもの, ugokimono) – things that move – and then add the sentence, 動くのなら、食べません. If it moves on its own (and not in search of photons to photosynthesize), they don’t eat it. This always gets the point across and makes people laugh as an added bonus.