Instructor List

Instructors with not only great variety of martial arts training, but great depth of training.  They measure their training in decades and train extensively in each method of martial arts they study.


Aikido Instructors


Brazilian Jiu-Jitsu Instructors


Judo Instructors


Karate Instructors




Aikido Instructors


Jason Tucker

Head Aikido Instructor / Dojo Cho

Jason Tucker is a Sandan (3rd degree black belt) with the Mid-America Aikido Federation. With over 20 years of training in Aikido.


Jason was introduced to martial arts in the early 1980's, and has been formally training for over 25 years.


In 2008 after relocating to Marshfield, Jason began running his own school of Aikido and training in Brazilian Jiu-Jitsu.  Now a blue belt in Brazilian Jiu-Jitsu (see under BJJ Instructor section).


Everyone who has spent time with Jason has noticed his constantly calm manor, his frequent humor, and analytical study of the world around him.  With Jason’s technical nature he quickly recognizes the science in his Aikido.  He balances that with dedicated attention to the flowing movement, and connection between people that has made Aikido famous.


Jason spends his days working as a Process Engineering Manager.  He makes his home in Marshfield with his wife, daughter, and son.



Douglas Mauritz


Douglas Mauritz is a Shodan (1st degree black belt) with the Mid-America Aikido Federation.


Doug was born in Alaska, and settled his roots in Central Wisconsin in his youth.


Doug began his Aikido training under Jason Tucker Sensei, and has been an active member from the start.  Doug brings a positive enthusiasm to his practice and instruction.  Doug embraces Aikido as a true Budo, working toward the same centered peace in practice and in his daily life.


Doug's military experience has left him organized and disciplined, and with an appreciation for fitness. 


Doug resides in Marshfield.




Joshua Mooney

Assistant Instructor

Joshua is a Ikkyu (2nd level brown belt) with the Mid-America Aikido Federation.


Joshua has had a broad exposure of martial arts.  Outside of Aikido he has trained in Karate, Jujitsu, Judo, and Tae Kwon Do.  This broad education is reflected in his strong body mechanics and application of movement.


Joshua resides in Anherst.




David Buehler

Assistant Instructor

David is a Nikyu (1st level brown belt) with the Mid-America Aikido Federation.


David resides in Marshfield.




Ellefson Sensei

Michael Ellefson

Chief Instructor

Michael Ellefson is a Godan (5th degree black belt) with the Mid-America Aikido Federation.


Mike is a full time martial arts instructor.  Teaching Aikido, Brazilian Jiu Jitsu, MMA, and training for law enforcement and businesses.


Mike began training in martial arts at age 11.  He has been training in Aikido for over 25 years, and training in Brazilian Jiu Jitsu for over 15.  He holds a 2nd degree black-belt in Ryukyu Kempo Karate, a 1st degree black belt in Brazilian Jiu Jitsu under Rigan Machado and holds rank in Judo, Shinbudo Crosstraining, and Shotokan Karate.  Mike continuously studies Japanese swordsmanship and uses the katana as a foundation of Aikido movement.


Mike approaches Aikido from both the martial and spiritual aspects. His techniques are known for being extremely effective and at the same time soft and relaxed.


Mike makes his home in North Hudson, WI with his wife and two daughters.


Brazilian Jiu-Jitsu Instructors


Cody Strey

Head Brazilian Jiu-Jitsu Instructor

Cody Strey is a purple belt in Brazilian Jiu-Jitsu.


Cody was introduced to martial arts through the art of fisticuffs (Boxing). Cody boxed throughout his teen years, adding up to almost a decade within the squared circle. After some time away from martial arts, Cody began training Mixed Martial Arts in 2012 and switched exclusively to Brazilian Jiu-Jitsu in the gi in 2013.


Working hard and committing himself to the art, Cody earned his blue belt from Garrett Erickson in 2014. Garrett earned his black belt from Luiz Claudio of Rickson Gracie lineage. Cody is currently a purple belt under Mike Ellefson, a Rigan Machado black belt.


Cody splits his time between the dojo, fitness endeavors and spending time with his loved ones.

Jason BJJ

Jason Tucker

Assistant Instructor (Head of Kids BJJ Program)

Jason Tucker is a blue belt in Brazilian Jiu Jitsu.


In 2008 Jason began running his first Aikido class at a Brazilian Jiu-Jitsu school, and started taking lessons from the instructor Garrett Erickson.  His early attempt to train was brief and inconsistent. In 2014 he begin steady training in Brazilian Jiu-Jitsu and has maintained that pace.


Jason runs the BJJ Kids and Family classes.



Ryan Jackson

Assistant Instructor

Ryan Jackson is a blue belt in Brazilian Jiu Jitsu.


Before moonlighting as a Jiu-Jitsu hobbyist, Ryan spent over a decade as an amateur wrestler for Loyal Wisconsin and UW-Stevens Point. After wrestling, Ryan joined the Army and naturally climbed the ranks of the Army Combatives program at an accelerated rate; he is currently a Level 4 Combatives Instructor.


In his personal life, Ryan is known for his cold humor, love for his family, and amazing ability as a marksman.



Mack Scheppler

Assistant Instructor

Mack Schepplar is a blue belt in Brazilian Jiu Jitsu.


Mack has trained under Cody Strey since 2014. Mack’s work ethic, persistence and can-do attitude are his most powerful assets that he brings to the gym; you can be certain he will be working hard when he steps foot on the tatami.


Outside of BJJ Mack is a competitive powerlifter, holding the Wisconsin state deadlift record within his weight class. 




Michael Ellefson

Head BJJ Black Belt (Affiliate Instructor)

Michael Ellefson is a 1st degree black belt under 8th Degree Red & Black belt Rigan Machado.


Mike has been studying Brazilian Jiu-jitsu since 1998. Mike first started BJJ in Rickson Gracie’s organization. He then earned his purple belt under 7th degree Rickson Gracie Black belt, Luiz Palhares. He then earned his brown and black belts from Professor Chris McCune and Master Rigan Machado.


Mike heads the BJJ program at his school (MCFM) in Hudson, WI.  Mike also oversees the BJJ programs at 10K MMA in Forrest Lake, MN and The Grind Fitness & MMA in Eau Claire, WI.


Judo Instructors


Cody Strey

Head Judo Instructor

In an effort to expand on the stand up techniques of his BJJ program Cody worked with other grappling experts such as wrestlers and Judo instructors.


Following this his students expressed interest in expanding their understanding of Judo. Cody agreed to build a fundamentals program under the guiding tutelage of Judo 8th Dan Rick Olstad and Judo Shodan Aaron Stinksi.



Karate Instructors


Harry Dolan

Head Karate Instructor

Harry Dolan began his practice of Shotokan Karate-do in 1978 and has been active ever since. He was awarded his Nidan (2nd degree black belt) by Tsutomu Ohshima in 1988. He has been a member of dojos in Windsor, Connecticut; Guilford, Connecticut (as leader); Madison, Wisconsin and Pittsburgh, Pennsylvania.


Harry moved to Marshfield, Wisconsin in 1994, but family commitments kept him from forming a dojo. He practiced alone for many years while maintaining ties to SKA. He recently founded the Marshfield Shotokan Karate Club and arranged to share practice space at Ki Nagare Dojo.