Dr. Okamura begins his circadian study from 1982 by the peptide work in the suprachiasmatic nucleus (SCN) using the technique of histochemistry. He established quantitative histochemistry in 80’s, and in vitro slice culture of SCN in early 90’s. In Kobe, Dr. Okamura had his own laboratory, and he and his team discovered a number of important molecular mechanisms in mammals including cloning clock genes, cell rhythm at single cell level, clock-regulation of cell cycle timing, and transduction of rhythm signals in the body. After moving to Kyoto in 2007, Dr. Okamura and his team widened their works not only in the basic molecular mechanisms of circadian clocks but also the translational research linking molecular clock and life-style related diseases. They discovered that methylation of messenger RNA alters the period length of circadian rhythms, and also isolated a critical novel steroid synthetic enzyme in salt-induced hypertension from mice with dyregulated clock. They also found a molecular mechanism of jet-lag. Dr. Okamura received Medal with Purple Ribbon from Emperor of Japan for his contribution to the study on circadian rhythms.