There's always something that drives people in this world, no matter how small or big it is.

In an underground city, known by no man or woman on the surface, a tree lies deep within its deepest parts, one per year giving the people of the city a treasure as gratitude for the kind and gentle care, a reward of various sizes; be it gold or gold, clothing or weaponry...

Due to conflict emerging through the decades, the citizens formed a contract; every year, on the exact day of the tree giving them their treasure, they would form a competition to choose the owner of it. Or that is how it was supposed to be, at least until someone chose to break the cycle...