Sitcom set in mid-1990s Derry/Londonderry, about the teenage Catholic school lives of the ubiquitious girls... and an English boy in the midst of The Troubles.

I believe the school uses an ex-Ulsterbus Tiger of some sort, painted yellow with the school name on the side. Didn't catch the registration, sadly.

Series 2, Episode 1 brings about Protestant school pupils to a unity team-building day that doesn't quite end well. If I recall, the Protestant school bus was a Mercedes-Benz minibus of some sort.

Series 2, Episode 3 entails the gang heading to Belfast on the 212 for a Take That concert. Their first means of getting there, though stopped when an 'unclaimed' suitcase full of vodka (owned by one of the girls) is blown up in a controlled explosion, involves travelling on preserved Ulsterbus Leyland Leopard 274 - YOI 2274.