A Single Shard tells the story of a 12-year-old boy named Tree-ear. He is an orphan and lives under a bridge in Ch’ulp’o, a small village in 12th Century Korea, with Crane-man, a crippled old man. Tree-ear scavenges for food most of the time, but after a full meal, Tree-ear loves to watch the potter, Min, make his pottery. One day, when no one is around, Tree-ear sneaks into Potter Min's house for a closer look at his creations. There are many objects, but one object particularly interests Tree-ear: a rectangular, lidded box. It is undercoated on the outside, but Tree-ear suspects that the inside is more spectacular. Out of curiosity, Tree-ear decides to look inside the box and finds five smaller boxes. They fit perfectly around each other. Potter Min shouts when he finds Tree-ear, who dropped the box in fright, breaking it. To repay the potter, Tree-ear offers to work for Master Min, and it is agreed he will work nine days, as the box took three days to make. Min assigns Tree-ear the task of collecting wood and clay for his nine days of work. Tree-ear is dismayed, for he secretly wants to make a pot. After his work days are completed, Tree-ear offers to work for the potter for free in hope of getting to make his own pot. Tree-ear is assigned various tasks including chopping wood and digging clay but never has the chance to make a pot. Tree-ear eventually learns that Min will not teach him how to make a pot because Min says that it passed down from father to son, and Min's son died of fever years ago. Emissary Kim arrives and inspects the pottery. Kang is chosen for the commission. Min begins work on a new set of pottery, but smashes them because they are not as good as he wants. Min makes two vases and tells Tree-ear to transport them to Songdo. During his journey, he is attacked by a few thieves.
When the thieves smashed the pottery, he is left with just a single shard to display his master's skill (hence the book's title). The emissary is able to see Min's great skill, even from the small, broken piece, and grants him a commission. After Tree-ear returns to Ch'ulp'o, he learns from Min that Crane-man has died. Min and his wife adopt Tree-ear, giving him a new name and finally teaching him the art of pottery.