Koji Arima

Koji Arima
Birthplace	Japan
Nationality	Japanese
Occupation	Business 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. Arima was elected to lead the company in June 2015, succeeding the previous leadership and guiding Denso through a period of significant transformation in the global automotive industry. During his tenure, the company navigated the shift toward vehicle electrification, invested in semiconductor partnerships, and received international recognition for its pioneering development of the QR code. In April 2023, Denso announced a change to its representative member of the board, marking the transition of leadership away from Arima's presidency. Under his leadership, Denso maintained its position as one of the top automotive parts suppliers globally, ranking as the second largest in the world by 2023, and played an active role in industry-wide initiatives to transform mobility in Japan and beyond.

Career

Rise to Denso Presidency

On February 3, 2015, Denso Corporation publicly announced its plans to elect Koji Arima as the company's new President and CEO, with the transition scheduled to take effect following the annual shareholders' meeting in June of that year. The announcement was made from the company's headquarters in Kariya, Aichi Prefecture, Japan. Arima's appointment placed him at the helm of a corporation that, at the time, was already one of the largest automotive component suppliers in the world, with operations spanning dozens of countries and a workforce numbering in the tens of thousands.

Denso Corporation, originally founded in 1949 as Nippon Denso Co. Ltd. after becoming independent from Toyota Motor, had grown into a global enterprise with deep roots in the Toyota Group while simultaneously diversifying its customer base to include major automakers in Germany, the United States, China, and throughout Japan. By the time Arima assumed the presidency, Toyota Motor Corporation held approximately 25 percent of Denso's shares, though sales to the Toyota Group accounted for less than half of Denso's total revenue, reflecting the company's broad reach across the global automotive supply chain.

Leadership at Denso

Arima's tenure as President and CEO of Denso coincided with a period of rapid change in the automotive industry. The global push toward electrification, the development of autonomous driving technologies, and increasing demand for advanced semiconductor components reshaped the strategic priorities of major automotive suppliers. Under Arima's leadership, Denso pursued several significant initiatives aimed at positioning the company for this evolving landscape.

One notable development during Arima's presidency 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, along with 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 semiconductor supply chains to the automotive sector, particularly as vehicles increasingly incorporated electronic systems for powertrain management, safety features, and connectivity. The partnership with TSMC and Sony underscored Denso's strategic focus on securing access to critical components for next-generation vehicles.

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 essential power semiconductor devices used in the inverters and power control systems of electric and hybrid vehicles. The commencement of mass production represented a milestone in Denso's efforts to build capacity in electrification technologies and to serve the growing global demand for electric vehicle components.

Industry Engagement and Mobility Transformation

Beyond Denso's internal operations, Arima was involved in broader industry efforts to shape the future of mobility in Japan. In October 2022, the newly established Keidanren Committee on Mobility was launched, attracting registration from over 200 companies and garnering significant attention within Japan's business community. The committee represented a cross-industry effort to address the challenges and opportunities presented by the transformation of transportation, including electrification, autonomous driving, and the integration of mobility services with broader societal infrastructure. Denso, as one of Japan's largest mobility suppliers, was a participant in these industry-wide discussions during Arima's tenure as CEO.

The company's engagement in such initiatives reflected Denso's broader corporate philosophy of contributing to societal progress through technology. Denso's involvement in collaborative frameworks with other Japanese manufacturers and technology companies was consistent with the company's historical position within the Toyota Group ecosystem while also extending its influence across a wider network of industry stakeholders.

Transition of Leadership

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 transition of executive leadership at the company. Arima's presidency had spanned approximately eight years, during which Denso had navigated significant industry disruptions, including the COVID-19 pandemic's impact on global supply chains, the acceleration of vehicle electrification, and heightened geopolitical tensions affecting semiconductor supply.

By the fiscal year 2025, Denso continued to report substantial financial performance, maintaining its position as one of the world's leading automotive parts suppliers. The company's consolidated structure encompassed approximately 200 subsidiaries across Japan, North America, Europe, Asia, Oceania, and other regions, reflecting the global scale of the enterprise that Arima had led.

Recognition

IEEE Corporate Innovation Award

One of the most prominent forms of recognition during Arima's tenure as Denso's President and CEO came in May 2023, when Denso received the IEEE Corporate Innovation Award for developing and spreading the use of the QR code. The award was presented at a ceremony, and Arima personally accepted the honor on behalf of the company. The IEEE Corporate Innovation Award recognizes outstanding innovation in technical fields, and its bestowal upon Denso acknowledged the company's role in creating a technology that has become ubiquitous across industries worldwide.

The QR code was originally developed in 1994 by Denso Wave, a subsidiary of Denso, as a means of tracking automotive parts during the manufacturing process. The technology subsequently found applications far beyond the automotive sector, becoming a standard tool for information sharing, mobile payments, marketing, logistics, and numerous other uses globally. The IEEE's recognition of Denso's contribution highlighted the enduring impact of the company's innovation capabilities, and Arima's role in accepting the award underscored his position as the public representative of Denso's corporate achievements during this period.

Company Rankings and Industry Standing

Under Arima's leadership, Denso maintained a prominent position in global industry rankings. In 2022, the company was listed at number 278 on the Fortune Global 500 list, with total revenue of approximately $49.0 billion and a workforce of 167,950 employees. By 2023, Denso was recognized as the second largest auto parts supplier in the world, a position that reflected the company's sustained growth and diversification across multiple automotive technology domains.

Legacy

Koji Arima's tenure at the helm of Denso Corporation coincided with one of the most transformative periods in the history of the automotive industry. The shift from internal combustion engines to electrified powertrains, the emergence of autonomous driving as a viable technology, and the increasing centrality of semiconductors and software to vehicle design all presented both challenges and opportunities for established automotive suppliers. Under Arima's leadership, Denso pursued strategic investments in semiconductor manufacturing through its stake in JASM alongside TSMC and Sony, advanced its capabilities in power electronics with the mass production of automotive IGBTs, and continued to leverage its legacy of innovation, as exemplified by the international recognition of the QR code.

Arima's presidency also saw Denso engage actively in industry-wide efforts to reimagine mobility in Japan, participating in cross-sector initiatives such as the Keidanren Committee on Mobility. These activities positioned Denso not merely as a component supplier but as a contributor to broader conversations about the future of transportation and its intersection with technology, energy policy, and urban planning.

The company's continued financial strength and global footprint during and after Arima's leadership reflected the effectiveness of the strategic direction pursued during his tenure. Denso's network of approximately 200 consolidated subsidiaries across multiple continents, its diversified customer base extending well beyond the Toyota Group, and its investments in emerging technologies collectively represented the legacy of the period in which Arima served as the company's chief executive.

Denso's ongoing work in areas such as additive manufacturing further illustrated the company's commitment to technological advancement that continued beyond Arima's presidency. Engineers at Denso's facilities in the United States described the company's work in additive design and manufacturing as representing "a new frontier" in the company's capabilities.