"Ma-konbu" (Saccharina japonica) belongs to belongs to the family Laminariaceae. It is a perennial brown algae that is endemic to Japan and is distributed from Hokkaido to the Tsugaru Straits and northern part of Iwate Prefecture. It is also cultivated in Japan, South Korea, China and Russia. It grows in shallow rocks with a depth of less than 20 m and is over 3 m high. The body is a long strip. There are wrinkles on the edges and they undulate greatly. Lifespan is 2 years. The leaves are thick and are considered to be the highest quality edible kelp, and are used for soup stock, tsukudani (kombu boiled in soy sauce), and tororo konbu (shredded kombu).