The reason is that when they were incorporated into the ward and given names in 1931, there were no houses in these towns since they were located in the mountainous regions.
これらは、いずれも昭和6年（1931年）に編入された地区であり、山間部などで、昭和6年の町名成立時において当該区域内に人家が存在しなかったものである。