In Japanese, an address is written from the largest area to the smallest: prefecture, city, district and finally the block and house number. In Roman letters the order is reversed, following Western conventions.
7820017
〒782-0017
高知県香美市
土佐山田町岩積1-2-3
山田 太郎 様
Japanese-style address
Taro Yamada
1-2-3 Iwazumi, Tosayamada-cho
Kami-shi, Kochi 782-0017
JAPAN
English-style address
1-2-3 is an example of the chōme, block and house number. Replace it and the name with the real ones.