The Hokuriku Area of Japan The length of Japan extends to about 300km. Included in this length about 1770km faces the Sea of Japan. The Hokuriku Area lies within this facing the Sea of Japan. It's about 770km from the most northerly tip and about 700km from the most southerly tip. This Hokuriku Area is about 300km in length, positioned right in the middle of the Japanese archipelago.