Martial Arts classes for people of all ages. Transported After School Program. In business for over 35 years. Welcome to Main Street Martial Arts, where we're helping men, women, and children across Napa get the very most out of life. Our family-friendly martial arts training is designed to help you stay active, safe, and confident. Our kid's program is the perfect way to teach students respect, discipline, and pride in everything they do. PLUS, our adult classes can equip you with real-world self-defense skills and an incredible total-body workout.