This is from my Ultimate Encyclopedia of Mythology:
Seven popular Japanese deities, the Shichi Fukujin, were considered to bring good luck and happiness. Each one personified a different aspect of good fortune. Although they were included in the Shinto pantheon, only two of them, Daikoku and Ebisu, were indigenous Japanese gods. Others were versions of popular Buddhist gods imported from China, while Benten and Bishamon originated as Hindu deities, and Hotai as a Daoist god. Buddhism was declared the official religion of the Japanese imperial court in AD 593, but instead of trying to stamp out the existing faith, Buddist missionaries in Japan drew parallels between the two faiths and proclaimed the identities of the deities to be the same. Because of this peaceable marriage of the two faiths, it was easy for attractive and popular Buddhist gods, such as those of good fortune, to be assimilated with the innumerable kami of the old religion.
Bishamon, the god of war, came from the Hindu pantheon. (Vaishravana, the Hindu god of fortune) He stood for benevolent authority. He was a warrior and always wore full armor, so that he was forever ready for battle. He is always shown carrying a lance and a miniature pagoda to symbolize his dual virtues as a soldier and a missionary.
Benten, the only goddess in the group of seven, was a goddess of love, and was believed to bring good luck in marriage. She rode on a dragon or sea serpent and was associated with the sea, so her shrines were often located by the sea or on islands. She was a patron of music and played a stringed instrument called a biwa. (Comes from Hindu goddess Saraswati.)
Fukurokuju, perhaps originally a Daoist sage, was the god of long life, wisdom, and popularity. He was a little old man with a short body and legs and a very long, narrow bald head, which indicated his intelligence. His traditional companions were animals associated with longevity: a crane, a stage, or a tortoise.
Hotei was a fat, bald monk who carried a large sack and a small screen. His enormous belly was meant to indicate his contentment and serene good nature, rather than greed. He is often depicted sitting comfortably on his sack, laughing merrily.
Jurojin was the godson of Fukurokuju, and also promised long life and a happy old age. He had a long white beard to indicate his great age and was portrayed carrying a staff to which was attached a scroll containing all the wisdom of the world, including the life-span of each individual.
Daikoku was the god of wealth and agriculture. He was portrayed wearing a cap and hunter's clothes, surrounded by the symbols of prosperity. Standing or sitting on a bag of rice, he carried another large sack of rice over his shoulder and a rice mallet in his hand, with which he granted wishes. He was sometimes said to be the father of Ebisu.
Ebisu was the Shinto god of work. The most popular of the seven gods, he was a fisherman, and was fat and cheerful. He was usually shown holding a large fish. Later, he became associated with profit and could bring good luck to commercial ventures. Ebisu was deaf, so he did not join the other gods for the Shinto festival at Izumo which takes place in October. Instead, his festival was held in his own temple.