Actually to be an Imperial Chrysanthemum it must have exactly 23 petals. The coin is 50 sen, or a half yen. It was from the 44th year of the Showa (Hirohito) era. Since he took the throne in 1925 it would then be a 1969 date. The first two figures in front of the 44 indicate the Emperor and the last simply indicates end. Pre war the info would have been right to left, with a + between the years. That was to indicate to add the two as decades and years, not as a simple 1 + 1 = 2.