At Cornerstone Martial Arts we believe in developing strength from within. Through our various classes - Kids Martial Arts, Adult Martial Arts, Fitness Kickboxing, and Adult Self-Defense - you can get super fit, expand your martial arts & self-defense horizons, or find an inspiring outlet for you children after school.

You'll learn effective, life-saving skills and while making a ton of new friends too!

The culture at Cornerstone Martial Arts is one where family always comes first and everyone is made welcome. Cornerstone is far more than just a martial arts school. It is a community!

Are you or your little one a total beginner? Or nervous to start something really cool but new? That's ok!

Our students come from all different backgrounds and professions, have widely different fitness levels and define unique goals for why they attend class. From beginners and elite athletes alike; all of our students get an amazing workout, gain lean muscle, and learn techniques to keep you and your family safe.

Expert Instructors Help You Reach YOUR Goals. Controlled, fast-paced, and fun movements in are peppered throughout every class. Our instructors love to motivate students in a positive way and will meet you where your starting level is.

You'll LOVE our curriculum, stellar class offerings, and the way your new physique will take shape!

Kids & Adults welcome! Some of our adult members are parents of our younger students, teens love to blow off steam with us and gain a positive body image, and kids have an absolute blast in our fitness featured high energy classes.

Youth & Adults Martial Arts are split so you get the most effective workout and learn skills suitable to your age and level.

Develop the heart of a champion with Fitness Kickboxing! Powerful striking, practical defense maneuvers, calorie roasting, heart-pounding cardio circuits help you develop the stuff champs are made of.

In all of our classes - both kids & adults learn how to be bully-proof, how to spot sticky situations so they can walk away before things get bad, and to defend themselves if they need to. Punching, kicking, self-respect, and respect for authority are the focus.

Below are some additional added benefits of our classes.


  • Boost Self-Esteem

  • Build Better Teamwork & Goal Setting Skills

  • Develop Outrageous Core Strength & Hip Mobility

  • Increase Fitness Levels

  • Have Boundless Energy

  • Gain Fit Friends For Life

Students use our classes as a highly effective training tool for personal defense, a stellar boost to weight loss and fitness gains, or even as a stand-alone martial art. We take great pride in making sure you have the most up-to-date, professional grade equipment, and a grime free environment to squash sickness and colds before they spread. That way you can train harder, and longer to meet your goals as quickly as possible!

Grab our super-low web special going on right now. Our classes fill up fast because it's such a great deal, reserve your spot today!

Get ready to experience the best prices, the most amazing staff, and have the most fun you've EVER had getting fit! Read a little about our leadership below. That way you can get a feel for the vibe our experts bring to our stellar curriculum. Looking forward to training with you soon!

Meet Rob Kloss
Owner at Cornerstone Martial Arts in Hockessin, DE
5th Degree Black Belt

Master Rob Kloss started training in Tang Soo Do karate in April of 1984 and became a full-time professional in 1990. He was the senior master at Hockessin’s Korean Martial Arts Institute for 25 years until taking over as owner on July 1st 2016.

His 35+ years of training have earned him master’s ranks with the World Tang Soo Do Association (6th Degree), World Sin Moo Hapkido Federation (6th degree) Korea Taekwondo Moo Duk Kwan association (7th degree) and Sin Moo Tang Soo Hapkido Federation (7th degree). He also holds a 5th degree Black Belt in WTF Taekwondo and a Level 7 Instructor certification in Unarmed Combatives with the Scientific Fighting Congress out of Denton, Texas. He has years and years of experience in teaching, training, competing in and promoting the combat arts. 

Master Kloss has trained literally thousands of students in his career and has successfully tested and promoted hundreds to black belt through one of the most demanding associations in the Korean Martial Arts world, the World Tang Soo Do Association. He is especially gifted at teaching kids!

Meet George Maybroda
Owner at Cornerstone Martial Arts in Hockessin, DE
4th Degree Black Belt

Master George Maybroda is known for telling his students, “Your life is an Occasion!!! Rise to it!!!” He started his Martial Arts training at the age of 12 at Diamond State Tae Kwon Do in the Coffee Run shopping center in Hockessin D.E.. That school would eventually become the Hockessin location for the Korean Martial Arts Institute years later. Master Maybroda trained under Thomas Murray for 2 years before circumstances cut his training short but that was far from the end of Master Maybroda’s love for the Martial Arts, or the journey he would soon take that would mold and shape his life.

March 15, 1993 a very overweight and out of shape George Maybroda wandered into the school at Coffee Run expecting to find his previous instructor -- instead he found Mr. Rob Kloss, the man who would be responsible for starting him on his life’s journey and purpose to teach and train martial arts professionally.

Maybroda lost the weight and began to get into shape. He started competing and assisting the then Mr. Kloss and Mr. Watters, who later to become Master Robert Kloss and Master Erwin Watters, with teaching class. Master Maybroda realized very quickly that personal high achievement in the martial arts is rewarding and necessary, but equally important and necessary is to show others how Martial Arts can positively change the course and direction of one’s life by giving students purpose, direction and a set of personal standards that students are required to hold themselves accountable to.

Master Maybroda has dedicated his life to being the best possible Martial Artist, Fighter and Teacher that he can be.

Since Master Maybroda started his journey he has achieved many successes such as achieving the ranks of 4th Master Tang Soo Do, 2nd Degree Black Belt in Tae kwon Do and Hapkido, Blue Belt Brazilian Jiu Jitsu, and currently trains and competes in traditional Thai boxing, Muay Thai.

Master Maybroda throughout his tournament career, has won over one hundred trophies for Point Karate and Olympic Style Tae Kwon Do and is a mutli-time Grand Champion. He currently trains and competes in full contact kick boxing at the age of 44, competing in both the USKA and the PRAKB.

He currently owns Maybroda’s Iron Circle Martial Arts in Malvern PA  and with this new Partnership with Master Rob Kloss is a co-owner of Cornerstone Martial Arts dedicated to preserving the traditions of the martial arts and setting the highest standards in Martial Arts Development and Achievement.  

Click on a program to get started today!

How to Get Started

Come join our Hockessin DE, facility! We offer programs in Kids Martial Arts, Adult Martial Arts, Kickboxing, Self Defense, Birthday Parties, and Summer Camp . Choose a program that most interests you and take the opportunity to sign-up right here on our site for one of our awesome web specials. Or feel free to give us a call at (302) 234-1966 if you have any further questions. We hope to speak with you soon!