[No. 106] Takeshi Toshimitsu

After graduating from the Department of Mathematics at the Faculty of Science and Technology in March 1995, I went on to complete my master's and doctoral degrees, finishing the Ph.D. program in March 2000. In other words, I spent a total of nine years studying at Keio's Faculty of Science and Technology, but for some reason, I am now working as an attorney. This time, thanks to a recommendation from senior and contemporary students from my math department days with whom I often spent time, I have been given the honorable opportunity to write for this Keio University alumni column. I would like to take this opportunity to look back on my campus life from the last century.

In high school, I was good at math but terrible at English. However, I was fortunate enough to receive a designated school recommendation and was accepted into the Faculty of Science and Technology at Keio University. If I recall correctly, in my time, the divisions were called "Kei" (tracks) instead of "Gakumon" (academic clusters). Since math was the only subject I was good at, I unhesitatingly chose Track 2, which included the Department of Mathematics.

Immediately after enrolling, I took to heart the shocking encouragement from a certain math professor who said, "If you can understand the textbook, you don't need to attend class." I completely turned into a delinquent student, neglecting even language classes and lab experiments that "required attendance," and thoroughly enjoyed my campus life.

However, in the second semester of my sophomore year, a moment I'll never forget, it seems my "savings" finally ran out. When I borrowed a friend's notes to study for the final exam in Mathematical Analysis (or something like that?), I found I couldn't understand even half of the content. I remember having no choice but to study desperately.

At the Faculty of Science and Technology, from the third year onward, we study at the Yagami Campus, located even further in than Hiyoshi.

As mentioned, with my "savings" depleted (and in the literal sense, too), I began to spend more time studying from my third year. During this time, I became interested in algebra, specifically the field of transcendental number theory within analytic number theory. It's hard to explain why, but in short, I think I was fascinated by the fact that "although transcendental numbers should be plentiful from a set theory perspective (i.e., an uncountable set), proving a number is transcendental is difficult." Then, when choosing a laboratory in my fourth year, I requested to join the lab of Professor Shiokawa, who would become my great mentor, and was successfully accepted.

In the fourth year, everyone starts their graduation research. In Professor Shiokawa's lab at the time, we held seminars where we read an introductory book on irrational number theory (in Japanese) in the first half of the year, and a foundational book on algebraic number theory and algebraic curve theory (in English) in the second half. Although both were basic-level books in their respective fields, I struggled quite a bit back then, being challenged by sharp questions from the professor and senior students, which really trained me well. Now, it's a fond memory.

The "second half" refers to my graduate school days. Since I spent five years in graduate school for my master's and doctoral programs, the second half was overwhelmingly longer.

The first year of the master's program felt like an extension of my undergraduate studies, and I recall having quite a few lectures. Then, I believe it was from the end of the first year into the second, I had my first opportunity to write a paper. (Note: At the time, few labs in the mathematics department required a graduation thesis.) This was another major challenge. From reviewing reference materials to figuring out how to derive results and how to summarize them concisely, I struggled immensely with both the input of studying and the output of creation.

However, as a result of the training I received then, I was able to write several papers afterward and proceeded to the Doctoral Program after completing my master's. In the Doctoral Program, research was the main activity. I read various papers, attended academic conferences, and sometimes presented my own research findings. I even went to conferences overseas. Looking back, I think I was leading a rather lofty life.

In March 2000, I successfully earned my degree and graduated. Since what follows is no longer about university life, I'll be brief. In April 2000, hoping to ride the internet venture boom, which was a mini-bubble at the time, I participated in establishing a computer software development company. However, the bubble didn't last, and our plans did not come to fruition...

After that, I worked at a think tank affiliated with a trust bank and started another business. Through these experiences, I came to feel that "accounting and law are essential to the foundation of business," and in April 2007, I entered Meiji University Law School. I'll skip the stories of my struggles in law school as I've written plenty about them elsewhere, but suffice it to say, switching to a humanities field in my mid-thirties was tough.

Then, in 2010, I successfully passed the bar examination, and after completing my legal apprenticeship, I am now working as an attorney. "Why on earth did you become an attorney?" is a question I've been asked at least a hundred times, but that's a story for another time.

Although I am still new to being an attorney, I strive every day to hone my skills, with the motto "strong with numbers," ensuring my logical thinking and numerical verification abilities are second to none. Furthermore, despite being a graduate of the Faculty of Science and Technology, as a lawyer from Keio University, it seems I will be allowed to join the Mita Hoso-kai (the Keio lawyers' association). This has allowed me to appreciate the strength of the Keio University network from a different perspective. The existence of an alumnus like me is a testament to the diversity of the mathematics department, and I would be happy if you would keep this in a corner of your memory.