Jun Akiyama wrote:
I can't say I've ever heard of "yon" being bad luck. "Shi" is also a homonym for "death" (shi), so I've heard some Japanese people do not like using that term and sometimes even the number (like the number 13 in Western cultures).
Just to add on to this... when I went to Japan, several of the hotels that I stayed in did not have a 4th floor because of the number "shi" (death). It was just like hotels here not having a 13th floor I was told.