The facility, intended to boost the fight against Somali pirates preying on vital shipping lanes, will be Japan's first foreign military base since World War II.
"This will be the only Japanese base outside our country and the first in Africa," said Japanese navy Capt. Keizo Kitagawa, commander of the Japanese flotilla deployed with the international anti-piracy task force in the Gulf of Aden. He will oversee establishment of the base.
"We're deploying here to fight piracy and for our self-defense. Japan is a maritime nation and the increase in piracy in the Gulf of Aden is worrying," Kitagawa said.
Setting up a Japanese base in Africa would have been unthinkable a few years ago under Japan's 1947 Peace Constitution, which forbade military deployments abroad. So the emphasis of the new venture is fighting crime -- the pirates -- rather than on military operations, even though Japanese troops have been deployed overseas since the early 1990s on U.N. peacekeeping missions.
Several Japanese vessels have been attacked by the Somalia pirates over the last couple of years and pressure from the country's shipping industry was apparently put on the government to step up anti-piracy operations.
The 150,000-ton oil tanker Takayama was hit by rocket-propelled grenades in a 2008 assault but was rescued by a German warship. In 2007, the chemical tanker Golden Mori was hijacked and released after six weeks, apparently after ransom was paid to the sea bandits.
Japanese officials say 90 percent of Japan's exports are shipped through the Gulf of Aden north into the Red Sea and the Mediterranean.
The new base is expected to be completed in 2011 and will include an airfield for Lockheed Martin P-3 Orion maritime patrol aircraft of Japan's military and a permanent port facility.
Japanese personnel are currently housed in accommodations rented from the U.S. base at Camp Lemmonier, a former French Foreign Legion installation near Djibouti's airport.
The camp, the only U.S. military base in Africa, is occupied by the Combined Joint Task Force-Horn of Africa, a counter-terrorism force deployed there after the Sept. 11, 2001, attacks.
China, which also has several warships attached to the international fleet, has also expressed interest in establish a naval base in the Gulf of Aden.
As with the Japanese, resupply and maintenance is difficult because of the vast distances between the region and their ships' home ports.
Japanese naval units, including missile destroyers and maritime patrol planes have been operating in the Gulf of Aden since 2009.
The Japanese contingent includes teams from the Special Boarding Unit, modeled on Britain's Special Boat Service.