Japanese lettuce is a plant of Asian origin. It is currently cultivated in temperate regions throughout the world. It is a mustard green plant with very characteristic leaves and a mild, sweet flavor.

Japanese lettuce is a rich source of vitamin C, a powerful antioxidant that strengthens the immune system, promotes collagen formation and improves iron absorption. Diets rich in vitamin C are known to be associated with a significant reduction in the risk of heart disease.