Mitama-cho(19342), Ichikawadaimon-cho(19343) and Rokugo-cho(19344) are merged, and Ichikawamisato-cho(19346) in Nishiyatsushiro-gun is newly established.
三珠町(19342)、市川大門町(19343)、六郷町(19344)が合併し、市川三郷町(19346)を新設