Not really. Each year 12 boy finds his level of "service". While Prefects at other schools have special ties, common rooms even food in dining rooms, the Joeys year 12 boys find an area that they can help and be an example. From Drama, to rowing, working in a Library, to coaching an Under 13 team, tutoring younger kids in Maths and French and even being a Dorm senior where they sleep (in a separate room) inside dormitory's with the younger years.
Joeys has never had any formalised school leadership and never will.