Complex sentence: One of the original manufacturers, Fukuya based in Nakasu Fukuoka, is the largest producer of mentaiko competes with over 150 other producers in Japan because they decided not to take out a patent on the recipe.
Split into simpler sentences: One of the original manufacturers, Fukuya based in Nakasu, is the largest producer of mentaiko. It has to compete with over 150 other producers in Japan because they decided not to take out a patent on the recipe.