The 2017 revisions to Japan’s curriculum introduced early English education in elementary schools. However, phonetic research on Japanese children’s English pronunciation is limited. Research findings have indicated low pronunciation accuracy for R, V, Z, P, and L. Reportedly, age and learning experience impact the acquisition of L and R. This study uses ultrasound images to examine the pronunciation of R and L by Japanese children, aiming to improve teaching methods by understanding the pronunciation challenges and individual differences.