The ads, which break this week, announce the station's new daytime line-up of Mike Toolan, Steve Penk and Justin Moorhouse.
But rather than appearing as DJs, the trio are shown in the fictional jobs they might have if they weren't signing up to Key 103.
They pose as solicitors, pest-control technicians and nightclub doormen before their true identity is revealed.
The voiceover says: "Toolan, Penk and Moorhouse, pest-control technicians from Whittington.
"Toolan, Penk and Moorhouse, security executives from Bolton.
"Toolan, Penk and Moorhouse is the new daytime line-up on Key 103."
The 30-second spot was written and art directed by Dan Norris and Naresh Ramchandani and directed by Zac and Dan through the production company Stink.
Media for the campaign was handled by Starcom Motive and will include a 48- and 96-sheet poster presence around Manchester.
The TV execution will run on Granada, which serves the greater Manchester area, and will run until the end of June.
Key 103's marketing director, Liz Larner, said: "Toolan, Penk and Moorhouse are household names in Manchester and we wanted to celebrate the fact that they're on Key 103.
"Raising awareness of our personality-led line-up will help to reinforce our position as the most-listened-to radio station in the area."
Karmarama won Emap Performance's £4 million creative account for its Big City Network of radio stations, which includes Key 103, in September after a six-way pitch.
The business was previously held by Faulds for three years, before the agency went into liquidation.
According to the latest Rajar figures, more people are listening to Key 103 and for longer. The station has 623,000 listeners each week, compared with 617,000 in the previous quarter, which gives it a 9.1 per cent share of its market.