It was on this little island facing Toba Harbour that Mikimoto Kokichi (1858-1954), known as "the pearl king", became the first person in the world to produce cultured pearls. The technique involves introducing a parasite into the shells of young oysters. Harvested after a minimum of four years, only 5% produce perfect pearls. There is a museum on the island that explains the process and has a display of jewellery and works of art made out of pearls. All year long, pearl fishing demonstrations by ama divers are organised.