During the “calculator wars,” manufacturers were struggling to create thin and cheap calculators for personal use. For this, improvements in large-scale integrated circuits (LSI) and keyboards were necessary. Yukio started working on the latter. At the time, there was a spring under each of the calculator’s buttons. Due to this, it was impossible to thin down calculators. Yukio focused on this problem and devised the plate spring type, which involves making cuts in the form of a spiral in a metallic plate and forming a spring-like shape. This allowed him to create cheap and thin keyboards, and the Casio Mini was born. Yukio said, “Engineers must come up with the simplest way to realize their goal. Simple is the best.” He believes that by removing all the unnecessary parts, small, cheap, and high-quality products can be made.

Early relay calculators experienced contact faults. To protect the accuracy of calculations, the lifeline of a calculator, Yukio revised the design of the relay device. He created a “double contact” with a U-shaped plate with two contact points, one of which would always be connected. This eliminated the contact fault problem.
Yukio, who developed this technology to preserve the originality of a small-scale calculator that could perform accurate calculations, would later lead technological development that would result in unique products. Believing the core technology the company excels at to be absolutely necessary, he mastered the technology needed to realize light, small-scale, thin, and power-efficient personal calculators, multifunctional watches, and digital cameras.

The four Kashio brothers felt relieved after successfully completing the relay calculator, but were left in the dust when it came to the digitization of calculators using transistors. They immediately switched to electronic calculators and recovered, but the experience led Yukio to say, “Technology is perishable. Even if you are using the latest technology, it will rot and become unusable as soon as you leave it alone. Manufacturers must always be aware of the world’s technological trends.” He stresses the importance of continuing to create new products instead of just holding on to past successes for manufacturers.

Since the dawn of Casio, Yukio has been involved in the design and manufacture of various products. Being responsible for turning Toshio’s ideas into reality, he says that excellent technology cannot be created in a day or two. “What creates new technology is the ‘engineer’s spirit,’ which is the ability to keep working tirelessly every day and pursue results until the end.” In 1983, Yukio developed the credit card-sized SL-800 calculator. It is stored in the Museum of Modern Art, New York City, as the technical end point of thin and small-sized calculators. “Technological prowess is the result of the accumulation of many years of effort by engineers. It is what allows us to create new products that have never been made before.” Yukio, who is an engineer, successfully grew Casio by devoting himself to study and continuing to develop original technologies.

Yukio became head of the production headquarters in 1965. He created a fully automated production line for calculators and established numerous production factories in addition to creating manufacturing technology for mass production. Yukio, who supported Casio with innovations in manufacturing technology, emphasizes the importance of seeing the production worksite with one’s own eyes. “If you take a look at the manufacturing process, you will be able to come up with ideas that lead to improved production. This will allow you to improve production efficiency and quality.” Yukio’s manufacturing technologies supported Casio in fulfilling its duty as a manufacturer to deliver higher quality products to more people than before.