Tin Man was awarded the contract as a result of its work for East Midlands Trains; both brands are part of Stagecoach Group.
The campaign is based on the insight that nearly one-third of student relationships fail due to the cost of maintaining their long-distance love.
Tin Man has created the Megabus Sweetheart Saver, a trial ticket offering free travel for couples in long-distance relationships between two of the 90 destinations on the network for a year. If the trial is successful, the ticket will be rolled out nationwide.
To launch the initiative, the agency worked with long-distance couple Jonny and Sofie, to produce a three-minute, cinematic film exploring the trials and tribulations of long-distance love.
Mandy Sharp, founder of Tin Man, said: "Our challenge was to position the brand as the obvious travel choice among students. We needed to find the deeper, more emotionally led benefits of how Megabus can become part of student life, to truly engage audiences."
Megabus says it carries four million passengers across the UK each year.
"This helps reunite friends, family and loved ones," said Megabus managing director Mark Venables. "We offer low-cost budget-friendly travel and hope that the new Sweetheart Saver ticket trial will enable more long-distance relationship flourish."