The contract, thought to carry fees in the region of £100,000, was won after a four-way competitive pitch and will see Harvard take over from four-year incumbent Golin/Harris International.
Board director Simon Jones will head a four-strong account team in the hope of introducing new consumer and commercial users to Plasmavision.
The team will work with Fujitsu's in-house marcoms team and report to Fujitsu European product and support manager Jonathan Perry.
Harvard MD Gareth Zundel said this marks a 'quantum shift' in the way plasma screens will be marketed: 'Our aim is to introduce people to an innovation that doesn't just improve on what went before, but provides the possibility of an entirely new theatrical experience in the home.'
The agency will target consumer and business audiences through a print and broadcast PR push and will oversee an imminent new product launch.
Japanese company Fujitsu was the first in the world to market and sell plasma screens, introducing the first display monitor in 1993. The company has around 180,000 employees in more than 100 countries.
Golin/Harris will continue to handle PR for Fujitsu's range of LCD projectors, while Tower PR has promoted their its air conditioner range for 12 years.