[6] From 1943 until the end of the Pacific War, Karafuto Prefecture (south Sakhalin) was designated part of the mainland.

Geographically speaking the term "mainland" is somewhat inaccurate, as this refers to an expanse of territory that is attached to a continental landmass.

The term "home islands" was used at the end of World War II to define the area where Japanese sovereignty and constitutional rule of its emperor would be restricted.

[citation needed] The term is also commonly used today to distinguish the archipelago from Japan's colonies and other territories.

[8] The five main islands, from north to south, are Hokkaido, Honshu, Shikoku, Kyushu, and Okinawa.