Madame Macmu-Ling was the master and teacher of the 5-7-5 Society, an organization devoted to the art of poetry, and was herself a master of the art of haiku. She always carried herself gracefully and could effortlessly and eloquently evoke imagery using her training and skill in poetry. Macmu-Ling respected and defended the complexities of the art and expected others to do the same. She also had little regard for those whom she believed were incapable of appreciating the high arts, and did not hesitate to use her craft to try and make such people look like fools. Madame Macmu-Ling lived in the Upper Ring of Ba Sing Se.
One day, when Sokka came crashing through a window of Macmu-Ling's haiku class and accidentally apologized in the form of a haiku, she greeted him with a somewhat badmouthing haiku in which she called him a "remarkable oaf", thus engaging them in a haiku duel. After an exchange of three haikus each, Sokka managed to win the poetry duel and Madame Macmu-Ling left the stage in defeat. However, when he recited his victory haiku, Sokka made a crucial error by using one too many syllables, for which he was abruptly thrown out of the room.