Idemitsu Kosan is one of Japan's leading petroleum refining and marketing companies, operating a network of service stations and supplying petroleum products to industrial and commercial customers across Japan. Beyond its core refining business, the company has been actively expanding into renewable energy, including solar power generation and solid-state battery materials for electric vehicles.

For international investors, Idemitsu Kosan is one of Japan's two major oil refining and petrochemical companies, with significant upstream exploration and production assets alongside its domestic refining network. The company has been expanding into renewable energy and battery materials, recognizing the long-term structural shift in global energy demand. Idemitsu's strategic evolution from a traditional refiner toward an energy transition participant is a central theme for investors assessing its long-term positioning.