Heal, the 17th prince of the Kingdom of Sanfaris was born with an unknown crest that he was unable to activate. Because of this useless crest, he was relegated to being lord of a remote island by his father, the king. Of course, there were no people there, nor were there any trees or plants. It was an island with just a single cave. However, the moment that Heal picked up the pickaxe inside of the cave, the ‘Cave King’ crest was activated. Its effect was specializing in mining, allowing him to efficiently mine all kinds of ore. Among the ore that could be mined on the island, there was even some ore that magic ability and ore that extended one’s lifespan… Heal would become so engrossed in mining, that he would eventually create the strongest country.