Geography of Japan
Japan is an island nation comprising a stratovolcanic archipelago over along East Asia's Pacific coast. It consists of 6,852 islands. The main islands are Honshu, Kyushu, Shikoku and Hokkaido. The Ryukyu Islands and Nanpō Islands are south of the main islands. The territory extends . It is the largest island country in East Asia and fourth largest island country in the world. Japan has the sixth longest coastline and the eight largest Exclusive Economic Zone of in the world.
Tatami
In Japan, the size of a room is often measured by the number of , about 1.653 square meters (for a standard Nagoya size tatami). Alternatively, in terms of traditional Japanese area units, room area (and especially house floor area) is measured in terms of "tsubo," where one "tsubo" is the area of two tatami mats (a square); formally 1 "ken" by 1 "ken" or a 1.81818 meter square, about 3.306 square meters.