It all begins with Luso dropping into the middle of a forest, right in front of a large bird: Klesta the Crushatrice, which Clan Gully had been hired to drive off. He is told by Cid that if he wishes to live, he should join his clan, Clan Gully. Luso excitedly does so, and, in front of a judge, swears into the clan, after which he magically transforms into a Soldier, complete with sword and fantasy garb. As a clan, they complete various quests throughout the game.
A brief description of Clan Gully (shown when it wins an area in an auction) says that it is little known, but with an impressive record of completed quests.
Clan Gully grows more and more popular as the game progresses, and as such they receive more Clan requests and more battle encounters from rival clans, but these battles take place usually after an auction. They also have allies and rivals in the clans House Bowen and Prima Donna.
"Gully" is an English word, meaning "a deep ditch or channel", possibly referring to the Rift. In Scottish it means "a large knife".