A more casual drinking cup, the thimble-shaped o-choko came into popularity during the Edo Period (17-19th century) as the popularity of sake spread to the common people. O-choko were traditionally made of earthenware and porcelain. The size of o-choko varies but typically holds only a few sips of sake. Small o-choko are often used to express a sense of empathy since when drinking with others it is not common to pour for oneself. In Japanese custom, the act of repeatedly pouring sake for a friend or guest shows non-selfish concern and is a display of courtesy. See "How To Enjoy Sake". Hokkan Sake. Retrieved 2014-11-06.