Yokoi was conscripted into the Imperial Japanese Army in 1941. Initially, he served with the 29th Infantry Division in Manchukuo. In 1943, he was transferred to the 38th Regiment in the Mariana Islands. He arrived on Guam in February 1943. When American forces liberated the island in the 1944 Battle of Guam, Yokoi went into hiding with ten other Japanese soldiers. He would remain in hiding until 1972. Seven of the original ten holdouts eventually moved away. Only three remained in the region. Later these last three separated, but they visited each other until about 1964, when Yokoi found his two friends dead, apparently of starvation. The last eight years he lived entirely alone.
Yokoi survived by hunting, primarily at night. He used native plants to make clothes, bedding, and storage implements, which he carefully hid in his cave.
Surrender
Yokoi was discovered in the jungle. He was found by Jesus Dueñas and Manuel De Gracia, two local men who were checking their shrimp traps along a small river on Talofofo. They had initially assumed that Yokoi was a villager from Talofofo, but managed to surprise and subdue him, carrying him out of the jungle with minor bruising. "It is with some embarrassment, but I have returned," he said upon his return to Japan. The remark would become a popular saying in Japanese. For twenty-eight years, he hid in an underground jungle cave, fearing to come out of hiding even after finding leaflets declaring that World War II had ended.