Idemitsu Kosan Co.’s oil tanker Idemitsu Maru (Panamanian-flagged), with three Japanese crew members aboard, successfully passed through the Strait of Hormuz on April 28 and is sailing toward Nagoya.
According to Iranian state media, the Idemitsu Maru, carrying 2 million barrels of oil—equivalent to about 0.6 day of Japan’s daily consumption—was authorized to pass through the strait, which has been effectively closed by Iran.
Following the outbreak of fighting between the U.S.-Israeli alliance and Iran at the end of February and the subsequent closure of the strait, this is the first Japan-related vessel to leave the Persian Gulf en route to Japan.
According to MarineTraffic, a website that tracks vessel positions, the Idemitsu Maru passed through the Strait of Hormuz at around 6 p.m. Japan time on April 28.
While transiting the strait, the ship did not display its destination, but showed “Nagoya” when it reached the middle of the Gulf of Oman. As of 7 p.m. on April 29, the Idemitsu Maru was sailing in the Arabian Sea, with an expected arrival in Nagoya in mid-May.
Japan’s Foreign Ministry announced on April 29 that a Japan-related vessel that had been stranded in the Persian Gulf had passed through the Strait of Hormuz and was sailing toward Japan. It also noted the three Japanese nationals on board.
Prime Minister Sanae Takaichi posted a comment on X (formerly Twitter) on the same day, saying that the Japanese government is engaging with Iran to ensure free and safe navigation through the Strait of Hormuz.
“We regard the passage of this Japan-related vessel as a positive development,” Takaichi added.
On the same day, the Iranian Embassy in Japan also posted on X a photo of the Nissho Maru, an Idemitsu Kosan’s tanker that purchased Iranian oil in 1953 while evading interference from the British Navy, at a time when Britain had imposed an oil embargo on Iran.
The Iranian Embassy added a message: “Its mission to transport Iranian oil to Japan stands as a testament to the long-standing friendship between the two countries. This legacy continues to hold great significance.”
According to the Japanese Shipowners’ Association, which comprises owners and operators of large vessels, 41 Japan-related ships remained in the Persian Gulf, with about 1,000 crew members aboard, including 13 Japanese nationals, as of April 29.
(This article was written by Fumiaki Sonoyama in Cairo and Takashi Yoshida in Tokyo.)

AloJapan.com