In the first half of the 1980s, construction of refineries advanced in Middle-Eastern oil-producing states, and in 1985 import of petroleum products by member states was discussed in an International Energy Agency cabinet-level conference.
While the rest of Japan's oil industry was opposed uniformly to such imports, arguing that they would bring about disorder in domestic markets and supply and demand conditions, Idemitsu alone supported liberalization of imports of petroleum products, arguing that free competition would vitalize businesses in the industry and benefit consumers. In 1986, with a framework that gives conditional permission for importation, the Provisional Measures Law on the Importation of Specific Kinds of Petroleum Refined Products (Specific Petroleum Law) was enacted.
This law had a fixed term of 10 years. As the trend over this period was one toward deregulation, there was intense debate over the continuation of the law. While those within the industry overwhelmingly favored its continuation, here too Idemitsu argued for its abolition, citing the need to build a strong oil industry that could stand up to international competition. Ultimately, after revisions to the reserve and quality-maintenance systems to maintain fair competition, the Specific Petroleum Law was abolished effective March 31, 1996.
Specific Petroleum Law Abolished

A self-service service station in Hachioji, TokyoSS
This brought about a major turning point in Japan's petroleum industry, promoting business restructuring in each field from purchasing of crude oil and petroleum products through production and distribution. Particularly in the area of retail sales at service stations, at the tip of the distribution system, regulations on opening service stations and Fire Service Act were revised, leading to the appearance of a variety of service-station types including self-service stations and multipurpose stations, as tough competition unfolded for survival in the marketplace.

Improvements to the distribution system advanced in response to liberalization.
Following amendment of the law, large 26-kiloliter tanker trucks made an appearance.
- Idemitsu Shokai Founded in Moji
- Overseas Branches Closed, Repatriation Begins
- Importing High-Octane Gasoline from the United States
- The Nissho Maru Incident: Challenging the Dominance of the Major Oil Firms
- Construction of Mammoth Tankers
- Completion of the Tokuyama Refinery
- Chiba Refinery Completed/Idemitsu Withdraws from the PAJ
- Idemitsu Enters the Oil Exploration and Production
- The First Oil Crisis and Advancing Overseas
- Specific Petroleum Law Abolished
- The Establishment of Idemitsu Credit and Development of the Credit-Card Business
- Outbreak of the Gulf War
- Introduction of Low-Benzene Gasoline