following year he was se-
lected to pass through
the Submarine School,
and in 1941 he was bil-
leted aboard the subma-
rine I-24. At this time,
Japan was preparing for
war with the United
States to obtain badly
needed raw materials
being denied by an eco-
nomic embargo. The first
step of Japanese strategy
entailed an attack against
Pearl Harbor, Hawaii, by
carrier forces as well as
submarines. For several
months up to December
1941, Hashimoto and the
I-24 were rigorously
trained in the transport
and deployment of minia-
ture submarines. His was
commanded by Sub-Lt.
Kazuo Sakamaki, a bright and enthusiastic
young officer. At midnight on December 6,
1941, I-24, in concert with 27 other such ves-
sels, launched miniature submarines against
the American fleet anchored in the harbor.
However, none scored any hits, and all were
destroyed. Worse, when Sakamaki’s vessel
floundered, he managed to escape and swim
to the beach—becoming the first Japanese
prisoner of war! Nonetheless, Hashimoto re-
turned to Japan, and the following spring he
gained assignment to advanced courses at the
Submarine School. This meant that a vessel—
and a command—of his own was in the offing.
In July 1942, Hashimoto assumed control of
the RO-44, a small submarine designed specifi-
cally for coastal patrol work. Over the next
two years he tirelessly honed and perfected his
skills as a commander, waiting for the day
when a large, fleet-class vessel would be his.
Hashimoto’s patience and persistence paid off
in May 1944, when he transferred to the I-58
with the rank of lieutenant commander. The
newly launched I-58 was a most impressive
warship. At 355 feet in
length, 30 feet across the
beam, and displacing
2,140 tons, it was nearly
twice the size of Ger-
many’s vaunted U-boats.
Furthermore, it possessed
a cruising range of 15,000
miles and carried no less
than 19 of the deadly oxy-
gen-powered Long Lance
torpedoes. These were
the most effective ship-
killing weapons any-
where, far more potent
than their American equiv-
alents. However, as the
months passed by, the I-58
was also rigged to carry a
new, more sinister de-
vice—the kaiten. These
were one-way suicide
subs manned by a crew of
two. The men chosen, usu-
ally fanatically trained college students, could
enter the kaiten only from within the sub-
marines carrying them, then were sealed off.
Their mission at that point was to strike an
enemy vessel or die. In January 1945,
Hashimoto led the I-58 out on its maiden com-
bat patrol and headed for Guam. There he
launched several kaitenswithout results—and
the experience of sending young men to their
doom affected him profoundly. Thereafter, he
swore not to launch any more of these ludi-
crous weapons unless success was absolutely
assured.
By the summer of 1945, Japan was on its
last leg, having lost the war badly. Its surface
navy had been crushed, and American ad-
vances in sonar and other detection devices
had sunk the majority of I-boats. This repre-
sented a great personal loss to Hashimoto, for
of the 15 highly trained individuals in his sub-
marine class, only five survived. Hashimoto’s I-
58 was one of only a handful of submarines
still operational. In July 1945, he was dis-
patched to perform one of the last JapaneseHASHIMOTO, MOCHITSURA
Mochitsura Hashimoto
U.S. Naval Institute