In his schooling years he read the Chinese classics and stories about the adventures of Christopher Columbus, Ferdinand Magellan, and John Franklin, and the latter third explorer inspired him to become an explorer of the Arctic.
He enrolled in elementary school in 1877, and graduated in 1879. In July of the same year he considered being a priest, but two months later he joined the military.
From 1881 to 1905, Shirase trained himself for an expedition to the Arctic. In 1881, Shirase completed an imperial Japanese army subordinate training program. He then joined the Transportation Corps and moved to Sendai.
The next year, he went to Utsunomiya to participate in more army activity and met Kodama Gentaro. In 1887 he married the daughter of a sea-based merchant and was promoted to a senior officer assistant and transferred to a military reserve.
In 1890, Shirase reunited with Kodama Gentaro in Sendai and talked about the thought of Arctic exploration, but Kodama was skeptical. Shirase joined the Chishima Exploration Party led by Meiji Gohji.
While arriving in the Chishima islands, a heavy rainstorm had caused a disaster resulting in 19 deaths. 9 members were left behind at the Shiashkotan islands, and 1 by the Paramushir. August 31 of 1893 the group finally arrived at Shumshu, the northernmost island of the Chishima chain. By the next May one more person died of Scurvy. In June, a Japanese warship docked at Shumshu. After 4 more members died and 5 disappeared, the group wished to return home on the ship, as was the district leader's plan. However the father of the district leader did not want the Chishima island expedition interrupted, and insisted the party remain on the island. After a cruel winter the district leader eventually consented to the return of the group. Shirase was one of four people who contracted scurvy, and the only one who survived it. Due to the disease Shirase lost strength and became unable to search for food. Out of necessity he shot and ate his pet dog in order to ward off starvation. By the time aid arrived, Shirase was no longer fit to participate in the first Sino-Japanese war. Shirase came to hold a grudge against the district leader and his family, and from that time after their relationship would only deteriorate.
Shirase and his men were the first humans to make a landfall on the Edward VII Peninsula. Although the Shirase party were scorned in their departure to Antarctica, they were feted as heroes on their return to Japan. In 1936, an exhibition was held in his honor at the Tokyo Science Museum, where records of his exploration and samples of Antarctica were displayed, and Shirase held a speech.
In September 4, 1946, Shirase passed away in Koromo-cho (now part of Toyota City), Nishikamo District, in Aichi Prefecture.
In 1887 he married the daughter of a sea-based merchant.