Casio

Casio was established as Kashio Seisakujo in April 1946 by Tadao Kashio (1917–1993), an engineer specializing in fabrication technology. Kashio's first major product was the yubiwa pipe, a finger ring that would hold a cigarette, allowing the wearer to smoke the cigarette down to its nub while also leaving the wearer's hands free. Japan was impoverished immediately following World War II, so cigarettes were valuable, and the invention was a success.

After seeing the electric calculators at the first Business Show in Ginza, Tokyo, in 1949, Kashio and his younger brothers (Toshio, Kazuo, and Yukio) used their profits from the yubiwa pipe to develop their calculators. Most of the calculators at that time worked using gears and could be operated by hand using a crank or using a motor (see adding machine).