Koji Arima

Koji Arima
Birthplace	Japan
Nationality	Japanese
Occupation	Corporate executive
Title	President and CEO (2015–2023)
Employer	Denso Corporation
Known for	President and CEO of Denso Corporation

Koji Arima (有馬 浩二, Arima Kōji) is a Japanese business executive who served as the President and Chief Executive Officer of Denso Corporation, one of the world's largest automotive components manufacturers. Elected to the presidency in June 2015, Arima led Denso through a period of significant transformation in the global automotive industry, overseeing the company's strategic expansion into electrification, advanced mobility technologies, and semiconductor partnerships. During his tenure, Denso maintained its position as one of the top automotive parts suppliers in the world, ranking second globally in the sector. Arima's leadership was marked by efforts to position Denso at the forefront of the automotive industry's shift toward electric vehicles, connected mobility, and advanced manufacturing processes. He accepted the prestigious IEEE Corporate Innovation Award on behalf of Denso in 2023 for the company's development and proliferation of the QR code, a technology originally created by Denso's subsidiary Denso Wave. In April 2023, Denso announced a change in its representative member of the board, signaling Arima's transition from the presidency.

Career

Rise within Denso

Koji Arima built his career within Denso Corporation, the global automotive components manufacturer headquartered in Kariya, Aichi Prefecture, Japan. Denso, originally founded in 1949 as Nippon Denso Co. Ltd. after becoming independent from Toyota Motor, grew into one of the largest and most diversified automotive suppliers in the world. The company is a core member of the Toyota Group, with approximately 21.25 percent of its shares held by Toyota Motor Corporation, though Denso serves a broad range of global automakers beyond Toyota.

Arima rose through the ranks of the organization over the course of his career at Denso, gaining experience across the company's diverse product lines and operational divisions. By early 2015, Denso's board of directors identified Arima as the successor to lead the company as it navigated an automotive industry undergoing rapid technological change.

Election as President and CEO

On February 3, 2015, Denso Corporation announced plans to elect Koji Arima as its new President and CEO, effective after the company's annual shareholders meeting in June of that year. The announcement was made simultaneously through Denso's corporate communications and picked up by international automotive media.

Arima assumed the presidency at a time when the global automotive industry was beginning a fundamental shift. Traditional internal combustion engine technologies were increasingly being supplemented or replaced by electrified powertrains, autonomous driving systems, and connected vehicle platforms. As one of the world's foremost suppliers of thermal systems, powertrain components, electronic systems, and information and safety products, Denso was positioned at the intersection of these transformative trends. Arima's appointment signaled the company's intent to accelerate its role in shaping the future of mobility.

Strategic Direction and Electrification

Under Arima's leadership, Denso pursued a strategy that emphasized electrification, advanced driver-assistance systems (ADAS), and connected car technologies. The company invested significantly in research and development to meet the growing global demand for electric vehicle components, including power electronics, thermal management systems for batteries, and electric motor technologies.

One of the notable strategic moves during Arima's tenure was Denso's decision to take a minority stake in Japan Advanced Semiconductor Manufacturing, Inc. (JASM), a subsidiary established in connection with Taiwan Semiconductor Manufacturing Company (TSMC). In February 2022, it was announced that Denso, alongside Sony Semiconductor Solutions Corporation, would invest in JASM as TSMC moved to establish semiconductor manufacturing capacity in Japan. This investment reflected the growing importance of semiconductors in modern vehicles and the automotive industry's response to the global chip shortage that disrupted production lines worldwide during 2020–2022. By securing a stake in a TSMC-affiliated manufacturing facility on Japanese soil, Denso under Arima's leadership sought to strengthen its semiconductor supply chain resilience.

Denso also continued to expand its electrification research and development capabilities during this period. The company opened dedicated electrification R&D centers in Japan to support the development of next-generation components for hybrid and fully electric vehicles.

Semiconductor and Electric Vehicle Component Production

In May 2023, Denso and United Semiconductor Japan Co., Ltd. (USJC) announced the mass production shipment of automotive insulated-gate bipolar transistors (IGBTs), targeting the expanding electric vehicle market. IGBTs are critical power semiconductor devices used in the inverters that control electric motors in hybrid and battery-electric vehicles. The commencement of mass production represented a significant milestone in Denso's efforts to become a key supplier of power electronics for the growing EV market. This announcement came in the final months of Arima's tenure as president, underscoring the strategic investments made during his leadership in building semiconductor manufacturing capabilities.

Mobility Industry Leadership

Beyond his role at Denso, Arima participated in broader industry initiatives aimed at shaping the future of mobility in Japan. In October 2022, the Keidanren (Japan Business Federation) established its Committee on Mobility, which drew registrations from over 200 companies seeking to drive all-Japan mobility transformations. The committee's formation reflected the Japanese automotive and technology industries' collaborative approach to addressing challenges in electrification, autonomous driving, and mobility-as-a-service. As the head of one of Japan's largest automotive suppliers, Arima and Denso were positioned as key stakeholders in these cross-industry efforts.

Advanced Manufacturing Initiatives

During Arima's tenure, Denso also advanced its capabilities in additive manufacturing (3D printing) and other innovative production technologies. The company's work in additive design and manufacturing was described by Denso engineers as representing "a new frontier" for the organization, with applications spanning materials engineering and component production. These efforts were part of Denso's broader strategy to adopt advanced manufacturing processes that could improve component quality, reduce production lead times, and enable the creation of more complex geometries for next-generation automotive parts.

Transition from Presidency

On April 10, 2023, Denso Corporation announced a change to its representative member of the board following a meeting of the Board of Directors. This announcement signaled the conclusion of Arima's tenure as president and CEO, a position he had held since June 2015. The transition came after approximately eight years of leadership during which Arima guided Denso through a period of profound industry change, including the acceleration of vehicle electrification, the global semiconductor shortage, and the increasing integration of software and connectivity into automotive systems.

As of the time of the board change announcement, Denso had grown to become the second-largest auto parts supplier in the world. The company had been listed at number 278 on the Fortune Global 500 in 2022, reporting total revenue of approximately $49.0 billion and employing 167,950 people worldwide. Denso's global footprint included approximately 200 consolidated subsidiaries spread across Japan, North America, Europe, Asia, Oceania, and other regions.

Recognition

Arima's tenure as President and CEO of Denso was marked by several notable recognitions for the company. Among the most prominent was the IEEE Corporate Innovation Award, which Arima personally accepted on behalf of Denso at a ceremony in May 2023. The award honored Denso for "developing and spreading the use of the QR code," the two-dimensional barcode technology that was originally invented in 1994 by Denso Wave, a subsidiary of Denso Corporation. The IEEE Corporate Innovation Award recognizes outstanding innovation in technical fields, and the recognition of the QR code—which had become ubiquitous worldwide in applications ranging from manufacturing logistics to mobile payments and digital health passes—represented a significant acknowledgment of Denso's contribution to global technology beyond the automotive sector.

The QR code was initially developed to track automotive parts during manufacturing but was made freely available through open licensing, enabling its adoption across virtually every industry worldwide. By 2023, the technology had become one of the most widely used digital interfaces in daily life. Arima's acceptance of the award on behalf of Denso highlighted the company's legacy of innovation and its willingness to share technologies for broader societal benefit.

Under Arima's leadership, Denso also maintained its ranking among the largest and most influential companies in the world, appearing on the Fortune Global 500 list and continuing to be recognized as a leader in automotive component technology and manufacturing.

Legacy

Koji Arima's approximately eight-year tenure as President and CEO of Denso Corporation coincided with one of the most transformative periods in the history of the automotive industry. When he assumed the presidency in 2015, the industry was in the early stages of grappling with the implications of vehicle electrification, autonomous driving technology, and increasing vehicle connectivity. By the time of his transition from the role in 2023, these trends had become central strategic imperatives for every major automaker and supplier.

Under Arima, Denso made strategic investments to position itself for this transformation. The company's investment in TSMC's Japanese semiconductor subsidiary JASM addressed the critical need for supply chain security in automotive-grade semiconductors, a vulnerability exposed by the global chip shortage of 2020–2022. The launch of mass production of automotive IGBTs with USJC demonstrated Denso's commitment to becoming a vertically integrated supplier of power electronics for electric vehicles. The expansion of electrification R&D centers strengthened Denso's engineering capabilities in areas that would define the next generation of automotive technology.

Arima also represented Denso on the broader stage of Japanese industry, participating in cross-sector initiatives to advance mobility transformation in Japan. His acceptance of the IEEE Corporate Innovation Award for the QR code underscored Denso's historical contributions to technology innovation that extended far beyond automotive applications.

Denso's continued position as the world's second-largest automotive parts supplier during and after Arima's presidency reflected the company's sustained competitiveness under his leadership. With a global workforce of nearly 168,000 employees and operations spanning more than 200 subsidiaries worldwide, Denso under Arima maintained its role as a critical node in the global automotive supply chain while actively investing in the technologies needed for the industry's future.