Masatosi OKOCHI became the RIKEN Foundation's third president. In 1922, he introduced a new system for organizing research at RIKEN. Under this system, laboratories were led by Chief Scientists who were given considerable autonomy to manage their respective research programs. He also established many affiliated companies that used RIKEN's research results to produce commercial products.

Kotaro Honda's research focused on metallurgy and magnetism. He earned great distinction early in his career by inventing KS magnet steel. Further development of this work enabled Honda to make major contributions to research on magnetism.
In 1922, he opened the RIKEN-Honda Laboratory at Tohoku Imperial University, where he continued his work, while encouraging scientists, such as Shoji Nishikawa, Hakaru Masumoto and Seiji Kaya .

Umetaro Suzuki was the founder of vitamin studies in Japan. His most important achievement was the isolation of what he named Oryzanin, or vitamin B1, from rice bran.The nutrient proved to be an effective cure for the debilitating disease, beriberi.
When the RIKEN Foundation was established in 1917, he became Director of its Chemical Division and undertook research on nutrition and food. He invented and developed products such as "RIKEN Vitamin" and a type of sake, "RIKEN-Shu," which differed from traditional sake in that it was made from materials other than rice.
Sales of these products provided RIKEN with an important source of income. He also applied his expertise to the development of agricultural chemistry and biochemistry, where he became an important source of inspiration for many promising young researchers.

In 1928, Yoshio Nishina published what became known as the Klein-Nishina formula, which now stands out as a major landmark in the history of quantum physics. Nishina was a Chief Scientist at RIKEN from 1931 to 1951, where he managed to foster a high level of understanding amongst his researchers. Nishina's wide range of interests included areas such as nuclear physics, elementary particle physics and cosmic-ray research. In 1948, the original RIKEN Foundation became a stock company, known as Kagaku Kenkyusho (KAKEN), or the Scientific Research Institute Ltd. Nishina became KAKEN's first president and served for three years.
Nishina inspired the development of many promising researchers, including the two Nobel laureates in physics, Hideki Yukawa and Sin-itiro TOMONAGA

Sin-itiro TOMONAGA joined Nishina's laboratory at RIKEN in 1932. In 1943, he published the "super-many-time theory," which reconciled quantum mechanics with the theory of relativity. Tomonaga further developed these ideas in his "renormalization theory," published in 1948. This new theory turned out to be the key to understanding quantum electrodynamics and, in 1965, he won the Nobel Prize in Physics.
Sin-itiro TOMONAGA joined Nishina's laboratory at RIKEN in 1932. In 1943, he published the "super-many-time theory," which reconciled quantum mechanics with the theory of relativity. Tomonaga further developed these ideas in his "renormalization theory," published in 1948. This new theory turned out to be the key to understanding quantum electrodynamics and, in 1965, he won the Nobel Prize in Physics.

In 1935, Hideki Yukawa published a theory proposing the existence of an elementary particle that produces an attractive force between the protons and neutrons within each atomic nucleus. The existence of the particle, called a meson, was later confirmed, and in 1949, Yukawa was awarded the Nobel Prize in Physics for his work.
Yukawa joined Nishina's laboratory at RIKEN in 1940 to work on theoretical physics. During the period 1961-67, he served as a RIKEN Chief Scientist.