this world is fantasy where at the mature age of your race(Human, kitsune, Dragon, Ogre, Troll and so on) you have a set amount of time to level up and gain skills; lets say for Humans, when they reach 15 they will be given a system in order to start levelling up. The system just shows stats, unallocated points and unfinished quests. after 10 years for a human(different for each Race) they will no longer be able to level up and will start upgrading their skills(the max rank skill being SSS)