The word for "four" has great significance to the Japanese, also.
As I understand it it is either the same as the word "death" or similar to it. Therefore 4 objects, and especially when in a symmetrical array, are not used. A gift of a set of tea cups, for instance, would contain 3 or 5, but not 4.
Good point, David. But I think this is more of a 'sound' phenomenon than a visual phenomenon. In Chinese, Japanese and Korean, the words for 'four' and 'death' sound very similar, but are written differently. As a consequence, a superstition has arisen, much like the superstition for the number 13 in the West.
However, I think the overwhelming connotations of 'four' are very positive. In Buddhism we have The Four Noble Truths which are at the foundation of all the teachings of the Buddha, namely, (1) Suffering, (2) Origin of suffering, (3)Cessation of suffering, and (4) Path to the cessation of suffering.
In fact, in religion, myth and history there's a wide spectrum of four-fold symbols. A few more which I haven't mentioned are, the four winds (Boreas, Eurus, Notus and Zephyrus), the four directions (north, east, south and west), and the four letters in the sacred name of God (YHVH).
We also have many examples of this 'quaternity' being represented in paintings of Mandalas, that can take the form of a cross, a star, a square, an octagon and so on. I rest my case.