Full Breakdown
Japanese Crude Supertanker Idemitsu Maru Crosses Hormuz Amid Ongoing Conflict
4/30/2026, 4:26:58 AM
Core Transit: Idemitsu Maru’s Passage Through Hormuz
On 28 April 2026 the Panama-flagged VLCC Idemitsu Maru, managed by a unit of Japanese refiner Idemitsu Kosan, completed a transit of the Strait of Hormuz carrying 2 million barrels of Saudi crude. The vessel entered the strait from the northwest of Abu Dhabi, followed a Tehran-approved northern lane near Qeshm and Larak islands, and emerged into the Gulf of Oman on 29 April. Its AIS remained active throughout the passage, and the ship is slated to arrive in Nagoya around 18 May.
Background: War-Induced Closure of the Strait
Since the U.S.–Israeli offensive against Iran on 28 February, the strait—through which roughly 20 % of global oil flows—has been effectively closed to most commercial traffic. Daily traffic fell from 125–140 vessels pre-conflict to seven ships in a 24-hour period on the day of Idemitsu Maru’s exit. The U.S. Navy imposed a naval blockade on Iranian ports on 13 April, while Iran required explicit permission for any non-Iranian vessel to use the waterway.
Diplomatic Efforts and Official Responses
Japanese officials have repeatedly urged Iran to restore free navigation. Prime Minister Sanae Takaichi posted on X: “We have taken every opportunity to urge Iran that it is crucial to quickly ensure the free and safe passage of all vessels, including those of Japan, through the Strait of Hormuz.” The Japanese Foreign Ministry echoed this stance, stating the passage was “a positive development… for the protection of Japanese nationals.”
Iranian state media (Press TV) reported that the tanker “successfully transited the Strait of Hormuz after securing permission from Iranian authorities.”
Idemitsu Kosan declined comment on individual vessels for safety reasons. The U.S. Treasury warned that “toll” payments to Tehran are sanctionable, and a U.S. official confirmed the vessel crossed the U.S. blockade line.
Data, Statistics, and Impact on Japan’s Energy Security
Japan imports ?90–95 % of its crude from the Middle East, historically via Hormuz. At the time of the transit, ?40 Japanese-linked vessels remained stranded in the Persian Gulf. To mitigate shortages, Japan released 30 days of strategic oil reserves in March and plans a 20-day drawdown beginning 1 May. Analysts note that even with Idemitsu Maru’s exit, “tanker and oil markets will not return to normal until at least September.”
Criticism, Sanctions, and Conflicting Reports
U.S. officials have criticized Iran’s toll system, labeling it a sanctionable offense. Sources differ on whether Idemitsu Maru paid a transit fee: Japanese media reported “no separate toll was paid… as a result of persistent negotiations,” while other reports noted the possibility of an undisclosed payment. Additionally, some tracking data showed the vessel’s AIS active, whereas other analyses suggest ships often switch off transponders when approaching Hormuz, creating uncertainty about exact traffic volumes.
Verbatim Quotes
- “We have taken every opportunity to urge Iran that it is crucial to quickly ensure the free and safe passage of all vessels, including those of Japan, through the Strait of Hormuz,” — Sanae Takaichi, Prime Minister of Japan, X post
- “Idemitsu has a long historical relationship with Iran, most notably the 1953 Nissho Maru incident, when Idemitsu transported Iranian crude oil to Japan under intense international pressure.” — Hidenori Watanabe, Professor, University of Tokyo
- “no separate toll was paid in the process, which is the result of persistent negotiations by the Japanese government.” — Japanese media, cited in Newsweek
- “Japanese VLCC Idemitsu Maru transits the Strait of Hormuz after getting permission from Iran, carrying 2M barrels of crude from Ras Tanura.” — Press TV
- “Iran has just informed us that they are in a 'State of Collapse'. They want us to 'Open the Hormuz Strait,' as soon as possible, as they try to figure out their leadership situation (Which I believe they will be able to do!),” — Donald Trump, Truth Social post
What’s Next: Ongoing Negotiations and Energy Strategy
Tokyo continues diplomatic outreach, with Foreign Minister Toshimitsu Motegi and Prime Minister Takaichi holding calls with Iranian officials. Japan plans to draw down additional strategic reserves while monitoring the status of the remaining ?40 stranded vessels. Analysts anticipate that further successful transits will depend on the resolution of the broader U.S.–Iran confrontation and the lifting of the U.S. naval blockade.
