Instructional Staff

The head instructor of the East Bay Judo Institute (EBJI) is Dr. David Matsumoto. In addition to his work at EBJI, he also serves as the Development Chairman for the United States Judo Federation (USJF) and as an Official Researcher for the International Judo Federation (IJF). Matsumoto Sensei is also currently an IJF Class “A” Referee and was the 2003 United States Olympic Committee’s Coach of the Year for Judo. He was also the 2002/2003 USJF Coach of the Year. In 2003, under the guidance of Matsumoto Sensei, students from the East Bay Judo Institute won 32 medals in Senior and Junior National and International Competition including 18 National or International Championships at the Junior, High School, and adult levels. Other accomplishments in 2003 include being co-author of a book describing 50 years of organized Judo in the US, International advisor to the Tokyo School of Judo Therapy, co-author of the 3rd International Judo Federation World Judo Conference and Judo Symposium (Osaka, Japan), and director of the 2nd US Judo Federation Conference (San Francisco).

Dr. Matsumoto is also a Professor of Psychology and Director of the Culture and Emotion Research Laboratory at the San Francisco State University. He earned his BA from the University of Michigan and his MA and PhD from the University of California at Berkeley. He has studied emotion, human interaction, and culture for over 15 years, and is a recognized expert in this field. He is the author of approximately 250 works on culture and emotion, including original research articles, paper presentations, books, book chapters, videos, and assessment instruments. He has made invited addressed to professional and scientific groups in the US and internationally. He also serves as an intercultural consultant to various domestic and international businesses.

Visit Matsumoto Sensei's website

Takenari Asanuma is a native of Japan and has been a member of EBJI for the past two years. He is a graduate of Kyobun College in Japan and specializes in Judo Seifuku Therapy. In addition to working with the competitors of EBJI, Asanuma Sensei performs various seminars educating people about Judo Seifuku Therapy and its applications. He has won multiple medals in National kata competitions for Katame-No-Kata and Kodokan Goshinjutsu. He is also the Medical Director for the United States Judo Federation. Asanuma Sensei currently resides in Richmond, California with his wife Makiko and their son.

Dan Israel is originally from Petaluma, California, and has been a member of EBJI for many years. He has competed successfully on the local and national levels. He is internationally certified as a judo referee (B referee license from International Judo Federation), as well as nationally certfied as an instructor and coach. He is also certified as a personal trainer and strength and conditioning specialist. Dan Sensei currently works full time as a computer programmer and part time as a personal trainer. In addition to this, he currently teaches intermediate and adult judo at EBJI as well as serving as president of Daiheigen Judo Yudanshakai.

Ken Kokka was born and raised in Berkeley, where he has spent his entire Judo career. Currently a 4th degree black belt, Ken Sensei has placed in various national championships, including the U.S. Youth National Championships and the U.S. Senior National Championships. He has also represented the EBJI in the trials for the Pan American and World Championships. His contribution to EBJI has been tremendous. Ken Sensei is currently a graduate student at the UCLA, majoring in film and has worked on major motion films such as Starship Troopers and Matrix Revolutions

"Teaching at EBJI has enriched my life immensely. I have met so many people that I love and respect through Judo, and through East Bay in particular, and I have developed relationships that will last a lifetime. Judo has given me an extended family that few are lucky enough to have. I try to take that feeling with me wherever I go, on or off the mat, as I believe that it makes me stronger and a better person."

Sayaka Matsumoto was born in Japan and raised in the Bay Area. She began studying judo at the young age of 5, under the instruction of her father, David Matsumoto. Sayaka’s love of judo has driven her to 8 Senior National titles, and the number one spot in the women’s -48 kg category. In 2000, Sayaka won a silver medal at the Junior World Championships, and has gone from there to represent EBJI in several World Championships. She currently teaches adult and beginning women’s judo class at EBJI and is a graduate of University of California at Berkeley.

"Being an instructor at EBJI has been a rewarding experience; I have learned not only judo skills, but skills that can be applied to my every day life."

Stephanie Hata was born and raised in the Bay Area. She began judo at the young age of 7 at EBJI, because she was prevented from participating in school PE and sports activities due to her small stature. Because of her determination, Stephanie has risen to one of the top ranked players in the women’s -48kg category and is the current senior national champion in this weight. She has represented the United States in various competitions around the world, including the 2001 Jr. Pan American Team and the 2002 Junior World Team. In 2003 she had a stellar year, winning Gold at the Jr. US Open and capturing a Bronze at USA Judo’s Fall Classic. Stephanie graduated from the University of California at Davis where she majored in Human Development.

"Judo at East Bay has taught me the true meaning of hard work."

Steve Hata was born and raised locally as has been a member of EBJI for over 10 years. He is the current Vice President of Operations and Development for Daiheigen Judo Yudanshakai and has made endless contributions to EBJI. In addition to working out with his children, Dale and Stephanie, Steve spends his judo career teaching the intermediate children’s class and beginning adult judo class.

"In judo, teaching is part of being a student and in judo you are always a student. When your students surpass you on the mat or in life then you know you’ve done your job as a teacher."

Themis Lonis was born in San Francisco and raised in Daly City. He began judo in 1995, mainly because it looked interesting and his children were also participating. He currently teaches children’s classes at East Bay twice a week and is a frequent member of the advanced class. Outside of judo, Themis is currently a Park Ranger for the Oakland Police Department and lives in Pinole with his wife Laura and their three sons, Daniel, Julian, Christian, and their daughter Emily.

Molly O’Rourke was born and raised in the state of Washington where she began practicing judo at the age of 13. In 2002, Molly made a huge commitment and moved to the Bay Area to train at EBJI and to pursue her dream of going to the Olympic Games. She has medaled several times in national and international competitions and competed in the 2005 World Championships in Cairo, Egypt. In addition to being an avid competitor, Molly also contributes her time to help teach the kid’s class at EBJI. She is currently a student at San Francisco State University where she is majoring in Kinesiology.

"Being a children’s instructor at EBJI has taught me a lot about the true meaning of patience."