Diamonds are the most powerful and the leaders. They never fight, they keep things in tracks.

Amethysts are the strongest above all. But strength doesn't make them win the Gemstones Event every year as they will compete with the intelligence of hunters from Garnet.

Sapphires are always the rebellious ones. They consider hunting as playing. When it comes to being unite they are the best.

The soldiers from Amber are the most creatives ones and they don't like to compete at all. What they like is to use their hands to make weapons and machines.

And for Emeralds... they are the ones no groups accept. The ones who are not good at anything. They have never won any Gemstones prizes nor have never hunt much vampires. You can say they are the weakest ones. Staying with them means death or living cowardly in shame.

No human can choose, leave nor change his group. Kim Jin Hwan was sure not potential as all. His weak body can't even make him run away from a vampire. He's the weakest in Emerald. But it's about to change when such a useless newbie like him has the power of making all the other groups' castles tumbling then fall down.