Curiosity killed the cat. It's the common phrase for those who are delving head straight into the unknown. But then, it is in man's nature to be curious. Many mysteries of the world have been unearthed and found an answer because of human curiosity after all. If not for it, the humans along with their lives will never evolve.
Celaeno is one such man. Even when he is just a kid, he questions almost everything regarding the existence of dungeons and its inhabitants. Born from a family with no remarkable wealth nor ideologies, he was planned to be raised as a hunter with the sole purpose of keeping their household together, to have food on their table.
But the more he delved into the dungeons, the more he became attracted to the existence of monsters. He does not want to just be a mere hunter for the sake of generating income. He seeked knowledge. Every time he joins a raid group, he would study on the side, collecting samples, observing the monsters.