Omura who turned 22 after his graduation from University of Yamanashi, became a teacher for night classes at Tokyo Metropolitan Sumida Tech High School starting April 1, 1958. He was busy everyday as it was his debut as a high school teacher. He taught both chemistry and physics, so he had to be well-prepared for his classes.
Since it was his first time to teach regular classes at school, he felt some anxiousness. In the past he had taken up part-time jobs as a private tutor, but teaching in front of a class required a different attitude.
At that time, the school’s nighttime department was short of physical education (PE) teachers, so Omura decides to teach PE as well. He loved sports and he was quite confident in competitive ski and table tennis.
In addition to that, a rewarding activity was added to Omura’s teaching life. He became an advisor to the school’s table tennis team. While he was enrolled at Nirasaki High School, he did a good job for his team. His skills were not rusted yet as no one from the Sumida Tech team could beat Omura in the game. Since the age difference was small, the team looked up to Omura as an upperclassman rather than a teacher. Omura casually mixed with the students. He coached the team with the goal of winning in the Tokyo Metropolitan High School Tournament.
The skills of the young players improved dramatically as they practiced daily. In 1958’s Tokyo Metropolitan Tournament, Sumida Tech kept winning in every preliminary game while everyone watched in amazement. In the end, the team managed to remain in the finals and achieved second place in the championship.
When Omura’s teaching life started to settle into a routine, it was time for the end-of-the-term test. He was to give basic problems to the students. But for the students, they were not easy to solve. After distributing the question sheet, the students began working on them avidly.
At one point, when Omura was going around the classroom during the test, he saw that one of the student’s fingers holding the pencil was soiled with grease. Students at nighttime high school usually work in a machine factory nearby the school during daytime, and by night they come to the high school to study.
Before arriving to class, students do not even have time to clear away the machine grease on their hands. Omura was quite moved by this incident and looked back on his own high school days.
He did not study much. He was immersed in ski and table tennis. He only started to study after fall in his final year. One could say that he fully “enjoyed” most of his high school days. At university, he was not completely devoted to his studies either. In retrospect, he felt that both his high school and university days were spent more on “enjoying” rather than studying.
On the other hand, his students who come to the night class work during daytime and study rigorously at night. At this point, Omura felt that he had to do something more. He decides to “re-learn.”
Omura thought he should study analytical chemistry more deeply. To do so, he had to be able to read foreign books and references. First, he went to a German language school and started studying. When he returned to Yamanashi during summer vacation, he visited Professor Senjiro Maruta, who was his mentor at University of Yamanashi. Omura told him about his determination to learn again.
In response to that, Professor Maruta introduces Omura to a professor at Tokyo Kyoiku University (later known as University of Tsukuba). When Omura visited this professor to express his wish to study more, he was introduced to Professor Koji Nakanishi who was famed in the field of organic chemistry.
From Professor Nakanishi, Omura learnt analytical techniques of chemicals and the latest methods in determining structure of chemical substances.
After a while, Professor Nakanishi introduces Omura to Professor Youjiro Tsuzuki from Tokyo University of Science (Department of Chemistry; Faculty of Science). Professor Tsuzuki has risen to become an internationally recognized researcher in the field of analytical chemistry and was known as a researcher familiar with foreign references and information.
In April 1960, Omura immediately enters graduate school at Tokyo University of Science. His full-scale learning scheme had begun. During daytime on weekdays, he would be busy attending lectures at Tokyo University of Science, to read related literature, and to devise experimental plans. Chemistry depends on experiments, so he needed extended time. It was not efficient to conduct experiments in small portions.
To overcome this problem, Omura decides to do his experiments throughout the weekend on Saturdays and Sundays. Once the experiment starts, there is no night or day. Omura brought his mountaineering sleeping bag into the lab and conducted his experiments nightly.
In one experiment, Omura flooded large amounts of water on the lab floor. The lab was located on the second level of the building right above Masaichi Majima, the office of the university’s President. Later on, he accidentally leaks water several times down to the President’s office.
Omura had analyzed and fixed chemical substances by applying NMR (Nuclear Magnetic Resonance), which at that time, was still at its earliest stage as a scientific discipline. Tsuzuki's laboratory was handling NMR’s latest technology, and Omura was blessed with luck to be able to take part in this research.
Omura who studies hard was acknowledged by many professors. He was highly regarded that he was chosen to read the congratulatory address at the university’s 80th anniversary ceremony, representing the student body.
At that time, Omura decides to marry a woman from Niigata prefecture who was introduced to him by his high school teacher. The woman was bright and full of life, but her father was a man of strict manners. On March 23, 1963 the wedding banquet was held at a Chinese restaurant in Kinsui Kaikan Hall located in Tokyo's Kinshicho Station Building.
Omura wrote his first academic paper just before completing graduate school. The paper was written in English. He posted it to the Journal of Japan Chemical Society. In it, he analyzed the three-dimensional structure of sugar using nuclear magnetic resonance (NMR) equipment. At that time, Tokyo University of Science was not equipped with NMR. Omura went to the Tokyo Industrial Testing Laboratory in Hatsudai, Shibuya-ku, Tokyo (later known as the Chemical Research Institute for Japan’s Ministry of International Trade and Industry) and to conduct his research.
In March 1963, after Omura managed to graduate his students, he leaves Sumida Tech High School’s teaching position which he held for five years and becomes a research assistant at University of Yamanashi.
In April 1963, Omura was assigned as an assistant to the Department of Fermentation Production, Faculty of Engineering, University of Yamanashi. This was a position especially prepared for him by his mentor, Professor Senjiro Maruta. With his newly-wed wife Fumiko, he went back to Yamanashi as a university researcher.
Omura's new boss was Professor Motoo Kagami, a professor of fermentation production at the Faculty of Engineering. His first study was on wine. The professor’s lab was studying yeast. This was Omura’s first encounter with microorganisms.
The amount of glucose in wine decreases over time, because microorganisms work to decompose glucose. When he learnt the power of microorganisms that can transform glucose into alcohol overnight, he was simply stunned. From this point on, Omura's life got intertwined with microorganisms.
At University of Yamanashi, however, most of the researchers seemed laid back. To Omura, it did not look like they were involved in cutting-edge research. Omura started to question this relaxed atmosphere, and decides to go back to Tokyo once more to work on research at a more substantial institute or university.
During such times, Omura hears that the Director of the Kitasato Institute, Dr. Toju Hata is recruiting one chemistry researcher for his lab. After applying to the position, he passes screening to become a member of the Kitasato Institute.
Omura bids farewell to his two years at University of Yamanashi and moves to a six-tatami mat room in Taimeiso Lodge, located at Seta 5-chome, Setagaya-ku, Tokyo.