1. Early Life and Education
Yūsuke Kobayashi's personal background and early involvement in judo laid the foundation for his distinguished career, leading him through the ranks of school and university competition.
1.1. Childhood and Introduction to Judo
Kobayashi was born on August 12, 1993, in Ageo City, Saitama Prefecture, Japan. He began his judo training at the age of six at the Himawari Judo Class, which was affiliated with the Ageo Police Station. He is known to have a B blood type and fights with a left-handed grip. His older brother, Daisuke Kobayashi, also became a judoka, competing in the -100 kg division.
1.2. School and University Judo Career
Kobayashi's academic journey through middle school, high school, and university was marked by significant achievements and a steady progression in his judo career.
1.2.1. Middle and High School Career
During his time at Saitama Sakae Junior High School, Kobayashi competed in the -90 kg category at the National Junior High School Judo Tournament in his third year, where he was defeated in the third round. Upon entering Saitama Sakae High School, he quickly made his mark. In his first year, he secured a third-place finish in the -90 kg division at the National High School Judo Championships. By his second year, he helped his team achieve a third-place ranking at the Kinkaku High School Judo Tournament. In his third and final year of high school, Kobayashi earned third place in both the individual and team events at the Inter-High School Judo Tournament.
1.2.2. University Career
In 2012, Yūsuke Kobayashi enrolled at Tsukuba University, where he continued to develop as a prominent judoka. His classmate was Takanori Nagase, who later became a world champion in the -81 kg division.
In his first year (2012), at the All Japan Junior Judo Weight Category Championships, Kobayashi defeated Mashu Baker, then a third-year student at Tokai University Urayasu High School, with an Uchi-mata in the semi-finals. However, he lost to Takao Omachi, a third-year student from Omuta High School, by a Yuko in the final, finishing in second place. That same year, he won the Asian Junior Championships and placed second at the Intercollegiate Weight Category Team Championships.
In his second year (2013), Kobayashi competed in the All Japan Judo Championships, reaching the third round alongside his brother, Daisuke. He claimed victory at the All Japan Junior Championships, defeating Omachi, whom he had lost to the previous year, with a Seoi Nage in the final. At the 2013 World Junior Judo Championships, he finished fifth in the individual competition and secured a third-place medal in the team event. In the Intercollegiate Weight Category Team Championships, Tsukuba University faced Tokai University in the final. Although Kobayashi lost to Baker by a penalty, his teammates, including Nagase, secured victories, leading Tsukuba University to their first championship title as a public university in this competition, breaking Tokai University's eight-year winning streak.
During his third year (2014), Kobayashi earned third place at both the All Japan Student Weight Category Championships and the Kodokan Cup All Japan Judo Weight Category Championships. In his fourth year (2015), Tsukuba University won the All Japan Student Judo Championships, defeating Tokai University, who were aiming for their eighth consecutive title. Kobayashi drew with Baker in his match, and the decisive victory was secured by Nagase, who defeated Aaron Wolf (then in the 100 kg class) by two penalties in the representative match. Later that year, at the Kodokan Cup, Kobayashi reached the final but was defeated by Kota Otsuji of Japan Ace Support by three penalties, finishing in second place.
2. Professional Judo Career
After graduating from Tsukuba University, Yūsuke Kobayashi transitioned into a professional judo career, joining corporate teams and continuing to compete at the highest levels.
2.1. Affiliations and Early Professional Activities
In 2016, Kobayashi joined Asahi Kasei, one of Japan's most prestigious corporate judo teams. This marked the beginning of his early professional activities. Later, in 2021, he joined Watanabe Densetsu, a company managed by his wife's family.
2.2. Major Tournament Highlights
Kobayashi achieved significant success in both domestic and international judo tournaments throughout his professional career, showcasing his skill and competitive spirit. His height is 69 in (175 cm) and his weight class is -90 kg. He holds the rank of third dan (san-dan).
In 2016, while competing for Asahi Kasei, Kobayashi reached the final of the Asian Judo Championships in the individual -90 kg category but was defeated by Komronshokh Ustopiriyon of Tajikistan, earning a silver medal. In the team event, Japan placed third.
In April 2017, at the All Japan Selected Judo Weight Category Championships, Kobayashi advanced to the semi-finals after his opponent, Mashu Baker, retired due to an old shoulder injury. However, he was then defeated by Shoichiro Mukai, a fourth-year student from Nihon University, securing a third-place finish. In August of the same year, he won the All Japan Corporate Judo Individual Championships. In October, at the Grand Prix Zagreb, he placed third after being defeated by Krisztián Tóth of Hungary in the quarter-finals. In November, he again took third place at the Kodokan Cup. In December, at the Grand Slam Tokyo, Kobayashi reached the final but lost to Kentaro Nagasawa of Park24 by an Uchi-mata makikomi very early in the match, resulting in a silver medal.
In 2018, Kobayashi competed in the All Japan Selected Judo Weight Category Championships, where he was defeated by Nagasawa by a hansoku-make (penalty loss) in the semi-finals, finishing in third place. He was subsequently selected for the Japanese team for the mixed team event at the Asian Games. In August, at the Grand Prix Budapest, he suffered a hansoku-make loss to Iván Felipe Silva Morales of Cuba in the second round. In September, at the Asian Games, during the mixed team event, Kobayashi was defeated by Gwak Dong-han of South Korea in their initial match, but the Japanese team still secured the win. He contributed to the team's victory in the semi-final against China and the final against Kazakhstan, helping Japan claim the gold medal in the inaugural mixed team event. He also won the Corporate Team Championships.
In 2019, he finished third at the All Japan Corporate Judo Individual Championships. In December 2021, competing under Watanabe Densetsu, Kobayashi participated in the All Japan Judo Championships, but he was defeated by Ryūnosuke Haga of Asahi Kasei via hansoku-make in the third round. In April 2022, at the All Japan Judo Championships, he lost to Kokoro Kageura, a judoka from the over 100 kg category, by a Yuko in the second round.
3. Personal Life
Beyond his professional judo career, Yūsuke Kobayashi's personal life includes his marriage to a notable figure in professional sports.
3.1. Marriage and Family
In February 2021, Yūsuke Kobayashi married professional golfer Ayaka Watanabe, who was a classmate of his during high school. According to Watanabe, Kobayashi entered her family by adopting her family name, becoming a member of the Watanabe household (a traditional Japanese practice known as `婿入りmukoiriJapanese`). It was also announced that Kobayashi would be leaving Asahi Kasei to join the company owned and operated by Watanabe's family, Watanabe Densetsu.
4. Coaching Career
After concluding his active competitive career, Yūsuke Kobayashi transitioned into judo coaching, sharing his expertise and experience with the next generation of judokas.
Since 2021, Kobayashi has served as a coach at his alma mater, Tsukuba University, where he previously honed his skills as a student-athlete. In 2023, he further expanded his coaching role by joining the KOMATSU Women's Judo Club, continuing his dedication to the sport's development.
5. Competitive Record
The following table provides a comprehensive overview of Yūsuke Kobayashi's significant results and rankings in various judo tournaments throughout his career.
| Year | Tournament | Result | Notes |
|---|---|---|---|
| 2010 | National High School Judo Championships | 3rd place (Individual), 5th place (Team) | |
| 2010 | Kinkaku High School Judo Tournament | 3rd place | |
| 2011 | French Junior International | 3rd place | |
| 2011 | Inter-High School Judo Tournament | 3rd place (Individual), 3rd place (Team) | |
| 2012 | All Japan Student Judo Championships | 5th place | |
| 2012 | All Japan Junior Judo Weight Category Championships | 2nd place | |
| 2012 | Asian Junior Championships | 1st place | |
| 2012 | Intercollegiate Weight Category Team Championships | 2nd place | |
| 2013 | Belgian International Judo Tournament | 1st place | |
| 2013 | All Japan Student Judo Championships | 5th place | |
| 2013 | All Japan Junior Judo Weight Category Championships | 1st place | |
| 2013 | World Junior Judo Championships | 5th place (Individual), 3rd place (Team) | |
| 2013 | Intercollegiate Weight Category Team Championships | 1st place | |
| 2014 | All Japan Student Weight Category Championships | 3rd place | |
| 2014 | Intercollegiate Weight Category Team Championships | 5th place | |
| 2014 | Kodokan Cup All Japan Judo Weight Category Championships | 3rd place | |
| 2015 | All Japan Student Judo Championships | 1st place | |
| 2015 | Intercollegiate Weight Category Team Championships | 5th place | |
| 2015 | Kodokan Cup All Japan Judo Weight Category Championships | 2nd place | |
| 2016 | All Japan Selected Judo Weight Category Championships | 3rd place | |
| 2016 | Asian Judo Championships | 2nd place (Individual), 3rd place (Team) | |
| 2016 | Kodokan Cup All Japan Judo Weight Category Championships | 5th place | |
| 2017 | All Japan Selected Judo Weight Category Championships | 3rd place | |
| 2017 | All Japan Corporate Judo Individual Championships | 1st place | |
| 2017 | Grand Prix Zagreb | 3rd place | |
| 2017 | Kodokan Cup All Japan Judo Weight Category Championships | 3rd place | |
| 2017 | Grand Slam Tokyo | 2nd place | |
| 2018 | All Japan Selected Judo Weight Category Championships | 3rd place | |
| 2018 | All Japan Corporate Team Championships | 1st place | |
| 2018 | Asian Games Mixed Team Event | 1st place | |
| 2019 | All Japan Corporate Judo Individual Championships | 3rd place |
6. Legacy and Impact
Yūsuke Kobayashi's contributions to judo extend beyond his individual competitive achievements. His career highlights his dedication and progression through the Japanese judo system, from his early days at a local dojo to national and international success. His disciplined approach and consistent performances in a highly competitive -90 kg category, which included victories against and close contests with world-class opponents, underscore his resilience as an athlete.
Furthermore, his transition into coaching at both Tsukuba University and the KOMATSU Women's Judo Club demonstrates his commitment to fostering the next generation of judokas. By taking on these roles, he contributes to the ongoing development of the sport, sharing his extensive experience and technical knowledge. His marriage to a prominent professional golfer also brings a unique connection between two different spheres of professional sports, occasionally drawing broader public attention to the personal lives of athletes. Overall, Kobayashi's career embodies the principles of hard work and continuous contribution to the judo community in Japan.