Most Chokos are made of ceramic but there are Chokos made of glass. Choko is also used as a vessel for dishes.
There is a white Choko which a double blue circle, which is called "Jyanome[蛇の目（じゃのめ）](snake eye)", is depicted on the bottom. This pattern is for examining the transparency of Nihon-shu by seeing the clearness of the border of white and blue color. Hereby, the taste can be guessed.
And a Choko for soup of Soba[蕎麦（そば）](buckwheat noodle) is called "Soba-choko[蕎麦猪口（そばちょこ）]". When eating cold Soba, that is dipped into the soup in a Soba-choko.
Choko is small and if you drink Nihon-shu from Choko, you may drink it up soon. Therefore, Nihon-shu is served in a tall vessel called "Tokkuri[徳利（とっくり）]" when drinking it from Choko.
And large-size Choko is called "Guinomi[ぐい呑み]". When drinking Nihon-shu from that, Tokkuri is not used.
Tokkuri is also used for pouring the soup of cold Soba into Soba-choko. That Tokkuri is called "Soba-dokkuri[蕎麦徳利（そばどっくり）]".
The term "Ochoko" is used as a metaphor for a small-hearted person. And that also refers to inside out umbrella.