What is the name of the cup used for drinking sake?

The name of the cup used for drinking sake is O-choko. This small cup is traditionally used for serving and enjoying sake, especially warm sake, as it is designed to fit comfortably in the hand and enhance the drinking experience. O-choko comes in various shapes and sizes, often made from ceramics or glass, and is commonly paired with a Tokkuri, which is the vessel used to hold and pour the sake.

The other choices refer to different vessels associated with sake but are not used specifically for drinking. The Masu, for instance, is a wooden box used for serving sake, especially in ceremonial settings, and it is more of a traditional serving method rather than a drinking vessel. The Tokkuri is indeed used for pouring sake but is typically a flask-like container rather than the cup itself. Jugo, on the other hand, does not refer to a standard term related to sake drinking. Thus, O-choko remains the correct designation for the cup in which sake is traditionally enjoyed.