2018 Portraits of Student Diversity at Keio

There is only one pair (up to similitude) of isosceles and right triangles for which the lengths of all sides are integers and which share the same perimeter and area. This was proven by a pair of Ph.D. candidates, Yoshinosuke Hirakawa and Hideki Matsumura, both members of Prof. Kenichi Bannai’s Arithmetic Geometry and Number Theory Mathematical Science Team. The problem was originally the brainchild of Matsumura, who invited senior classmate Hirakawa to work with him on the project. “Hirakawa is fascinated by the beauty of integers,” Matsumura says, and together they took four months to prove their theorem. Their findings were published in an American academic journal and even made national headlines here in Japan. Both aspiring researchers, they say they hope to take on other problems in the future to prove to the public that the world of mathematics really is a fascinating place.

(This article originally appeared in the Winter 2019 (No. 301) edition of Juku)

Yuka Kobayashi joined the Keio University Baseball Club as chief manager during the Spring 2018 season just as Keio clinched two back-to-back Tokyo Big 6 Baseball League titles for the first time in 27 years. She also accompanied the national collegiate team Samurai Japan as manager when it won the 6th FISU World Collegiate Baseball Championships in Taiwan that July. “I’ve had some wonderful experiences,” she beams. Born into a family of avid baseball fans, Kobayashi has baseball in her blood. She was always excited to watch high school baseball as a student at the Keio Girls Senior High School and became a manager of the Keio University Baseball Club as soon as she got to university. In her third year, she was approached by the coach about taking on the position of chief manager. She readily agreed, stating that she would love the challenge of doing something no one had ever done before and has served admirably in the role since November 2017. Her burning desire for success shows no signs of slowing with a job offer from an advertising agency following graduation: “I’ve always wanted to work in the media,” she says.

(This article originally appeared in the Autumn 2018 (No. 300) edition of Juku)

Taro Yoshimura has been collecting shellfish since he was in elementary school. In junior high school, he stumbled upon a fossilized bay scallop in his home of Fukui prefecture, which was officially recognized as a new species by the paleontology world and published an international journal. He was just 14 at the time. “There was a heated debate among experts,” he says. “But in the end we were confident that we had discovered a new species.” Yoshimura sustained his interest in mollusks throughout his time at Keio Senior High School, winning best presentation at a poster session for his research into the sexual dimorphism in bivalves at an academic conference in Malaysia. More recently he has turned his attention to research on the advantages of shellfish as a material. A student of economics at Hiyoshi Campus, Yoshimura goes to Mita Campus twice a week to study for curatorial qualifications. He maintains a wide range of interests and says, “I really want to broaden my view of society and learn to appreciate the values of different disciplines.”

(This article originally appeared in the Summer 2018 (No. 299) edition of Juku)

Dozens of Keio banners flap in the wind on the side of the road accompanied by the cheers of even more fans. For Negishi, the 94th Hakone Ekiden marathon in 2018 was the race of his life. Sheer determination helped him keep his college grades up even as he maintained a strict running regimen. During the 2017 tryouts, he ran the 20 kilometer in 1:00:58, shaving almost three minutes off his time the previous year. As a member of the Kanto Region University Student United Team, he ran the eighth section of the Hakone Ekiden in 2018. For the Keio Track and Field Club, where coach Kosaku Hoshina has started the Keio Hakone Ekiden Project, Negishi’s appearance is a huge step in the right direction. The next step is taking the entire Keio team to Hakone, Negishi says: “I brought back a lot of experiences from Hakone, and I want to share that excitement with my teammates.”

(This article originally appeared in the Spring 2018 (No. 298) edition of Juku)