Oh I never known about meaning of Japanese number before.
It's very interesting and surprising!

Some group of Thai people (not the majority) don't like no. 4 as well because 4 is pronounced "Si" which quite similar to "death" in Chinese word. However there is "4" in every place including hospital in Thailand ^^.

The unlucky number in Thai is quite the same as western country. It's "13".
There is no floor #13 in almost every building in Thailand. They use "12A" instead.

On the opposite way, not only "9", but "8" is also another lucky number since it's the chinese lucky number and there're many chinese people in Thailand :)

Additional Tips: no. "5" in Thailand is pronounced "ha". If you chat with Thai people, you'll see they always type "555555" to show they're laughing.
So 55555... means hahahah... something like that ...^_^