I also want to add, that in some ways, the Japanese can express themselves far more viciously than a western use of a swearword.
if a Japanese person wants to be sufficiently aggressive, they might simply say "drop dead". to us, it doesn't really mean much, it's said so often that there is no real meaning, but in Japanese to say this, it is laced with so much venom that it can be considered a heinous insult. It can probably hold a lot more weight than any of our swearwords.
sorry I'm taking this off topic.