Army school was pretty good at football (Birendra shield) and then later it was Galaxy school with their junior ANFA team members

Anyway

St.Xavier's vs Budhanilkantha (Boka school rivalry)
St.Mary's vs Triyog (Bakhri school rivalry, I heard they had competition at who would say "chyaaa" the most and who could talk NepEnlgish combo the most)

those were pretty big back in the day