Toshio Kashio (1925–2012) was a Japanese inventor and a central figure in the founding of Casio Computer Co., Ltd. As the second eldest of the four Kashio brothers, his technical vision and commitment to digital innovation transformed a small family workshop into a global leader in electronics and horology.

Born in Tokyo on January 1, 1925, Toshio was inspired to become an inventor at the age of 12 after reading a biography of Thomas Edison. He studied electrical engineering and began his professional career in 1940 as a technical officer at the Ministry of Communications. In 1946, he joined his older brother Tadao at the newly established Kashio Seisakujo. Toshio’s early inventiveness led to the creation of the yubiwa pipe, a finger-ring cigarette holder that became a commercial success, providing the capital necessary for the brothers to pursue more ambitious electronic projects.

Toshio’s primary contribution to the company’s early success was the development of the 14-A, the world’s first compact all-electric calculator, released in 1957. Unlike contemporary calculators that used gears and motors, Toshio’s design utilized 341 relays to perform complex arithmetic. This breakthrough led to the formal establishment of Casio Computer Co., Ltd. that same year. Toshio served as the company’s head of development, focusing on his philosophy that “invention is the mother of necessity”—creating products that generated new consumer demand rather than simply responding to existing needs.

In the 1970s, Toshio transitioned his expertise in digital calculation to the field of horology. He conceptualized the wristwatch not merely as a display of time, but as a device that adds up seconds. This led to the 1974 release of the Casiotron, the world’s first digital watch featuring an automatic calendar. Under his guidance, Casio continued to innovate throughout the 1980s and 1990s, introducing calculator watches, the Databank series, and foundational technologies used in the G-Shock line.

Beyond timepieces and calculators, Toshio was instrumental in developing electronic musical instruments. At age 55, he began researching the “consonants and vowels” of sound, which resulted in the 1980 release of the Casiotone keyboard. Toshio held over 300 patents during his lifetime and served as Chairman of Casio from 1988 until becoming Honorary Chairman in 2011. He passed away in May 2012 at the age of 87. His former home in Tokyo now serves as the Toshio Kashio Memorial Museum of Invention, preserving his legacy of digital innovation.