This exploratory study examined the impact of Heroes Circle, a martial arts-based curriculum on stress, emotional, and behavioral problems in elementary school children. While students completed classroom surveys at baseline, post-curriculum surveys were collected from teachers, students, and parents/guardians 2 and 5 months after COVID-19-related school shutdowns. Satisfaction with the curriculum was high among those who received the intervention. Children reported increased mindfulness and decreased stress over the school year. Most children (77%) were still using the program's techniques and reporting benefits 5 months later, including lower internalizing symptoms and COVID-19-related fears. These patterns were not observed at the control school.