But the annual Easter School at St Mary's University College Belfast drew more than 250 pupils from across the west of the city this week.
Classes are targeted at those who require extra support in preparation for GCSE Maths and English.
Four days of tuition are offered to schoolchildren who are at risk of not achieving a pass grade.
Geraldine McAteer of the West Belfast Partnership Board, which manages the programme, said demand for places is high and pupils are "incredibly keen" to take part.
Ms McAteer puts the popularity of the classes down to the environment and ethos of the school, which is one of "relaxed but focused learning".
"They're mixing with children their own age, from other schools, in their own clothes, their civvies," she said.
"They're in a university environment, working with different tutors and university students who volunteer to shepherd them around. So it has actually gained a reputation as quite a fun experience.
"A grade C is a passport to so much, so this is to help get them over the line," said Ms McAteer.
Maths tutor Jim Stott said the additional support often provides the encouragement students require to keep on studying at a time when their predicted grades may discourage them.
"They're keen to tell you what exact areas they need more support with.
"It may be trigonometry or algebra, so we break them up into small groups and when they're getting the extra attention, they soak it up. They're really committed to it.
"It's very relaxed - I'm not standing at a board talking to children, the children are taking part in it. Sometimes they're at the board.
"Pupils tend to gel together very well. They're not necessarily from the same schools, and that's part of the attraction - they like to mix with young people from other schools."
Ms McAteer explained that the Â£25 fee is waived for those who cannot afford it.
"This is a great social justice model," she said.  "We raise money from the Department of Education which enables us to pay for tutors and hire of premises.
"There are some people who can afford to pay that amount per hour. But this is 16 to 20 hours tuition for Â£25.
"But if we find out from the school that a family can't afford that cost, it's overlooked. Our main aim is to get the pupils in, to give them assistance, to get them to pass."
Ms McAteer said the West Belfast Partnership Board hope to roll the programme out to other parts of the city over time.
It's a strange phenomenon - teenagers opting to return to the classroom over the Easter Holidays.