Kazuo Kashio, a marketing virtuoso whose family company, Casio Computer, popularized the pocket calculator, the shock-resistant wristwatch and the preview screen on digital cameras, died Monday at a hospital in Tokyo. He was 89.

The cause was pneumonia, the company said.

Kashio, who headed the family company for nearly three decades, was credited as the salesman who turned Casio’s innovative mini-calculator into a universal device and revamped the image of the wristwatch from a dainty, elegant timepiece when it introduced the rugged, knobby, retro G-Shock. Last August, Casio turned out its 100 millionth G-Shock since the watch was introduced in 1983.

Kashio and his three brothers transformed Casio from a homegrown backyard machine shop into a global company, with $3 billion in annual sales of digital watches and cameras, calculators, electronic keyboards and other musical instruments, and high-speed printers.

Casio Computer was born as Kashio Manufacturing in 1946 in the rubble of post-World War II Japan when Kazuo Kahio’s older brother Tadao conjured a finger-ring cigarette holder that would allow the wearer to smoke down to the filterless butt in tobacco-starved Japan.

Anointing their father as the company’s first president, Tadao, Kazuo and their two other brothers renamed the company Casio in 1957 — they westernized their surname to broaden the company’s appeal in postwar world markets — and transformed it, investing the considerable profits from the popular cigarette ring in research and the development of other devices.

Kazuo Kashio, the company’s gregarious retailing specialist, was president from 1988 until 2015, when he became chairman and chief executive, posts he held at his death. He was succeeded as president by his oldest son, Kazuhiro.

Kashio was born on Jan. 9, 1929, in Kureta-mura (now Nankoku), in southern Japan, to Shigeru and Kiyono Kashio.

His father was a rice farmer who moved to Tokyo with his family and became a construction worker, helping rebuild the city after a devastating earthquake in 1923. To save money, he walked to and from work, for a total of five hours.

Kazuo graduated in 1949 from an English course affiliated with Nihon University in Tokyo. In 1950 he joined his brothers Tadao and Toshio at the fledgling consumer goods factory that was churning out the cigarette rings and a corn biscuit baker. Tadao had worked in a munitions plant and made airplane components during the war.

In the early 1950s their fourth brother, Yukio, an engineer, joined the firm. By 1957 they had perfected an innovative electronic (rather than electromechanical) calculator that could not only add and subtract but also multiply. It weighed 308 pounds and sold for the equivalent of $11,000 in today’s dollars.

By 1965, Casio was producing desktop calculators. In 1972 the company introduced the Casio Mini, billed as the world’s first personal calculator. It became ubiquitous after a prodigious marketing campaign.

While European craftsmen scoffed at electronic watches, Casio perfected quartz and digital models sold under the motto “Time is a continuous process of addition.”

In 1974, the company unveiled the Casiotron, a digital wristwatch that displayed a calendar in addition to the time.

The G-Shock, of which there are now hundreds of models, boasted not only durability but also longer battery life than its competitors. It was heavily promoted through, among other marketing tools, product placement in films like “Men in Black” and “Mission: Impossible.”

The Casiotone-201, an electronic musical keyboard, was introduced in 1980, followed by the QV-10 digital camera in 1995 and pocket televisions, word processors, car navigation systems, blood pressure sensors and more.

Kashio is survived by his wife, Soko, as well as two daughters, a son and his brother Yukio. His brother Tadao died in 1993. His brother Toshio, who invented some of Casio’s products, died in 2012.