Barkeep is a Hypello in Final Fantasy X-2 who works with the Gullwings. Although the specific details are not known, Brother found Barkeep and took him aboard the Celsius, the Gullwings' airship. Barkeep runs the "bar" aboard the ship, and, as no one knows his actual name, he is simply referred to as Barkeep.
Barkeep runs a shop Yuna can buy curative items and accessories from. He also gives the option to rest, and, although the save spheres completely heal the party, resting does have a function.
If the party rests once per chapter, after resting for the final time an extra cutscene is played showing Brother and Barkeep talking about Brother's infatuation with Yuna, and Barkeep reveals he has a partner called Darling, much to Brother's dismay. From this point, players can rename the animals that appear when using the Trainer dressphere.