Both of my boys are taekwondo students at AMYS Martial Arts in Utah and we LOVE it (someday I just might become a student). I do some design work for them, including designing t-shirts when needed. 2017 is the 7th year in a row they've been Utah State Champions and I've had the privilege of creating t-shirts for the last few years to celebrate.
For 2017, they decided to have two colors printed... for the folks who baby don't want to wear gold (like me!).
In addition to the above t-shirts, I also created this fun ninja t-shirt that both kids and adults enjoy wearing. They printed it on both red and royal blue t-shirts.
Years back, someone created a little somewhat-Anime-style character for the studio. I redrew it, made some changes, and gave the little guy some new poses. I also created a girl version, a ninja version (below), Ninja Santa, Ninja Easter Bunny, Ninja Valentine, and more depending on the event or holiday. My oldest son loves to wear his Ninja in Training t-shirt.
If you live in Salt Lake or Utah county, I HIGHLY recommend checking out AMYS Martial Arts for your family. They have studios in Draper and Orem and lots of options for class times and days, including Saturdays. Classes start for kids as young as age 2 all the way up to adults, and ALL skill levels and athletic abilities are welcome. Students work on tumbling, flexibility, and strength training, along with taekwondo discipline. There's a lot of focus on building a strong character both inside and outside the studio. My son has to have his room clean and his teacher has to sign off when he's testing for a new belt. He's had to learn his phone number and address, anti-bullying strategies, and how to count in Korean. They offer week-long summer camps, an after school program, a monthly Parent's Night Out, and seasonal picnics and parties. Seriously worth checking out!