Goishicha is a fermented green tea from Ōtoyo in Kochi prefecture of Shikoku island. To make Goishicha the tea leaves are steamed, stacked, covered with a mat and then fermented. After that the tea leaves are filled into a barrel where a weight is placed on the top to continue fermenting. Finally, the tea is dried in the sun. The tea is called "Goishicha" because it looks like stones from the Japanese game Igo (in western countries also known as "Go").