Mmm... I still think it's a bit iffy, but if you say so...

Hm... Well, to put some ideas forward...

In both scenarios, the characters need motivation. 

In a school... Well, what's the school for? How does it work? History of the school? What makes it important/special? etc; etc; etc;

For a tournament... Occasion? Location? Host? Reward? Format (round-robin, double-elim, single-elim, etc;). 

If you've decided on one idea or the other i could probably go more in depth on that one.