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11165 San Pablo Ave
El Cerrito, CA 94530


David Matsumoto Sensei

Hachidan – 8th Degree Black Belt

Founder and Program Advisor

The founder and program advisor of the East Bay Judo Institute (EBJI) is Dr. David Matsumoto. Matsumoto Sensei served as head instructor of EBJI from 1983-2015 and currently holds an 8th degree black belt (Hachidan), an International Judo Federation “A” Level Referee License, an “A” Level Teacher and Coach Certificates from the United States Judo Federation. He is also a licensed instructor in all seven katas of judo. In addition to his work at EBJI, he had also served as the Chairman of the National Technical Research Subcommittee of the USJF, as an Official Researcher for the International Judo Federation (IJF) and as Director of Development for USA Judo.

Matsumoto Sensei has received numerous coaching awards, including the 2003 United States Olympic Committee’s Coach of the Year for Judo and 1999 US Olympic Committee’s Developmental Coach of the Year in Judo awards. He was also recently inducted into the 2021 USJF Hall of Fame which aims to acknowledge outstanding judoka who have made significant contributions to judo. His students have distinguished themselves many times as medal winners in many national and international tournaments; as national and international referees; as organizational leaders in judo; and as social and civic leaders.

Professionally, Dr. Matsumoto is Professor of Psychology and Director of the Culture and Emotion Research Laboratory at the San Francisco State University and Director of Humintell, LLC. 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 30 years, and is a world-renowned expert in this field. He is the author of approximately 400 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 and agencies.

Dan Israel Sensei

Rokudan – 6th Degree Black Belt

Head Instructor

Over 30 years ago, Dan Sensei was draw to EBJI by its reputation for good, hard training. He began his tenure at EBJI as a visitor, by making hour-long commutes from the Petaluma area before becoming a permanent and essential fixture in the dojo community.

Since then, he has become a well-rounded judoka; he has enjoyed competitive success on the national level while also being certified as a national coach and teacher. Dan Sensei also has basic mastery of all seven katas as well as being very well-versed in the history and evolution of judo.

He is the former President of Daiheigen Judo Yudanshakai and holds an IJF “A” Referee License (the highest certification for referees). In addition to his work as a computer programmer and teaching judo, Dan Sensei represents EBJI nationally and internationally as a referee, and has served as the head instructor of EBJI since 2015.

Ken Kokka Sensei

Rokudan – 6th Degree Black Belt

Senior Instructor

Ken Sensei is the longest standing members of the East Bay Judo Institute, and is universally respected as a role model to the younger instructors.

Ken Sensei enjoyed a successful competitive career as a two-time medalist at the Senior National Championships, and qualifier for the Pan American and World Championship team trials.

As a visual effects supervisor for Netflix he has worked on a number of major motion pictures, commercials and television projects.

After earning his graduate degree in film studies at the University of California, Los Angeles in 2006, he continues to work in the film industry, and on his own personal projects. Ken Sensei currently assists Sayaka Sensei with the competitor’s class.

Sayaka Torra Sensei

Rokudan – 6th Degree Black Belt

Senior Instructor

SayakaMatsumoto2008_000 - CopySayaka Sensei began studying judo at the age of 5, under the instruction of her father, David Matsumoto, and grew to become a talented judo player in her own right.

She currently has the most impressive list of competitive accomplishments: She is a 7-time Senior National Champion, competed at 3 World Championships, and was a member of the 2008 Olympic Team in Beijing.

She graduated from the University of California at Berkeley with a B.A. in Mass Communications and a minor in Japanese.

Since retiring from competitive judo, Sayaka Sensei now teaches both the beginning children’s class and competitor’s classes at EBJI. She currently works as a business operations manager for Humintell, a psychology-based company located in the Bay Area.

She, her husband and son live in Pinole with their dog, two cats, and multiple beehives.

Nate Torra Sensei

Yondan –4th Degree Black Belt

Senior Instructor

Nate Sensei began Judo at the age of 4 in Massachusetts, where he was born and raised. After winning various junior national competitions located around the country, Nate Sensei relocated to upstate New York and won his first Senior National Championship Title in 2001, when he was only 18.

After medaling in many other Senior National Championships, Nate relocated to California in 2006 and joined EBJI shortly thereafter.

While a member of EBJI and under the guidance of Matsumoto Sensei, Nate won his second Senior National title in 2008 and also competed and place third at the US Olympic Trials that same year.

He currently holds a license in massage therapy and works as a massage therapist, owning his own private practice. Nate also holds a personal training certification through NASM.

Satoshi Matsumoto

Sandan – 3rd Degree Black Belt


Coming from a judo family, Satoshi began judo at the young age of 5.

He received his black belt in 2016 alongside his twin brother, Masashi.

A multiple Jr. National Medalist, Satoshi teaches the beginning kids class once a week.

He recently graduated from UC Davis and currently is in a teaching credential program where he has aspirations of becoming an elementary school teacher in the future.



Masashi Matsumoto

Sandan – 3rd Degree Black Belt


Masashi began judo at the young age of 5.

He received his black belt in 2016 alongside his twin brother, Satoshi.

A multiple Jr. National Medalist, Masashi assists in teaching the beginning kids class once a week.

He graduated from Sacramento State with a degree in Criminal Justice and currently is in the police academy with aspirations of becoming a law enforcement officer.



Nico Gonzalez

Nidan – 2nd Degree Black Belt


Nico began judo at EBJI over 10 years ago in 2008. He and his sister had tried other martial arts before finding their home at EBJI.

Within the last decade, Nico has become an excellent role model for our younger judoka, excelling in both athletics and academics.

After winning several national competitions at the junior level, Nico decided to switch his focus to academics.

He obtained his degree from the University of San Francisco and recently graduated from law school and passed the CA State Bar exam.


Yoshiki Castillo

Nidan – 2nd Degree Black Belt


Yoshiki began judo in 2004 at a local boys and girls club at the age of 5.

After wanting to become more serious about competitive judo, he switched to EBJI in 2012 and hasn’t looked back since.

Since becoming part of the EBJI family, Yoshiki has become a strong competitor, winning medals at national level tournaments including a gold at the 2018 USA Judo Jr. Olympic Championships (International Division).

Yoshiki is currently an EMT and is attending paramedic school with future hopes of becoming a fire fighter.

Keith Berry

Nidan – 2nd Degree Black Belt


After studying MMA, and Chinese Martial Arts in the mid-late 1990’s, Keith Berry started Judo in 1998 at age 20.  Initially drawn to Judo by its systematic approach to grappling, Keith also found Judo to have strong cultural and moral dimensions that were lacking in other martial arts.

After completing his undergraduate education at UC Berkeley in 2003, Keith was drawn to East Bay Judo by its reputation for producing good fighters, as well as its motto of “Building good people through Judo.”

Keith has enjoyed multiple stints as a student at EBJI in 2004-2005, and 2012 through present. Keith is the proud father of EBJI students, Tewodros “Teddy”, Daniel, and Salome.

Keith is the Responsible Managing Officer of Apt Maintenance Inc in Oakland, CA and recently received his MA in Theology from the Graduate Theological Union in Berkeley. He currently lives with his wife Sarah Abigail Ejigu and their 3 children in the East Bay.

Brenna Clark

Nidan – 2nd Degree Black Belt


Brenna began judo at 6 years old and received her shodan (black belt) from Okubo Judo Club at age of 16.

The head Senseis at Okubo, Haruo Makimoto Sensei and Kuniko Takeuchi Sensei fostered a love of training and competing in judo within her. In high school, Brenna cross-trained at both Okubo and EBJI.

She graduated from Harvard Extension School and with a degree in Humanities.

She is currently building her career as a realtor in the Bay Area and assists with the children’s class twice a week.

Brenna is pleased to observe the joy and growth her daughter, Zoey is experiencing from learning judo at EBJI.

Takashi Matsumoto

Nidan – 2nd Degree Black Belt


Alongside his brothers (Satoshi and Masashi), Takashi began judo at the young age of 5.

He received his black belt in 2018 and has placed at the Junior National Championships several times.

Taka graduated from El Cerrito High School and currently attends UC Berkeley. He hopes to have a career in film in the future.


Ben Phelps

Shodan – 1st Degree Black Belt


Ben started at East Bay Judo Institute in 2011. Prior to starting judo, he studied Shodokan Aikido for 11 years.

He graduated from Cal State East Bay with a degree in Administration of Criminal Justice. In addition to practicing judo, Ben also studies Brazilian Jiujitsu.

He currently is a defensive tactics instructor at Berkeley Police Department where he has been an officer for 17 years.

Ben assists with the Monday night kid’s class (where his son is a student) and also attends the adult class on Tuesday evenings.

Jason Buchholz

Shodan – 1st Degree Black Belt


Jason Buchholz first stepped onto the mats in seventh grade, as an 84-pound wrestler for Lawrence Cook Jr. High School, in Santa Rosa, CA.

In high school he switched his studies to a dojo that taught tang soo do, kickboxing, and arnis, and then as a student at UC Berkeley he trained in taekwondo, eventually earning a black belt.

He was away from martial arts for many years, until a fellow parent recommended EBJI as an activity for his preschool-aged son. After watching a few classes, Jason turned in his own paperwork, tied on a white belt, and entered the adult class as a forty-year-old beginner.

A few months after his 49th birthday, he earned his shodan. Jason trains in the Tuesday adult class and teaches in the MW kids’ class.

Professionally, Jason is a co-founder and co-owner of Collaborist, a company that provides coaching, editing, and writing services for aspiring authors.

He is the author of the novel A Paper Son, which examines the trans-Pacific immigrant experience to California of a century ago.

He has also had a long career in early childhood education, where he developed skills and experience he brings to the kids’ class. He lives in Richmond with his son and daughter.