It happened in Kirkcaldy on Saturday morning.
Police said a 14-year old boy got off his bus in the town’s Hendry Road around 10:55am.
He was followed by a man and a woman who demanded he hand over his property, before assaulting him..
Police said the man was in his 30s-40s, around 5ft 6, slim build and was wearing a black jacket. The woman was estimated to be in her 30s-40s, around 5ft 4, with long black hair and was wearing a purple jacket.
Detective Sergeant Andrew Miller, from Glenrothes CID, said: “This was an unprovoked attack and a distressing experience for the teen victim, who was fortunately not seriously injured as a result.
“We believe a number of members of the public and passing motorists witnessed the incident and are appealing for anyone to come forward.”
Call police on 101, quoting incident 1167 of 14 November.