'Sho 4' was the Japanese plan within 'Sho' for the strategic defence of Hokkaido island and the Kurile islands group (summer 1944).

The plan was ready for implementation at the end of October 1944, with its final development embodied in 'Ketsu' of December 1944, which added the defence of the southern half of Sakhalin island to the original scheme. The defence was allocated to General Kiichiro Higuchi’s 5^th Area Army (five divisions and two independent mixed brigades) answering directly to Imperial General Headquarters in Tokyo.