Overgeared

Shin Youngwoo is a pure loser in life who is also heavily indebted to an insurance company. He lives with his disappointed parents and brilliant younger sister who is one of the top students at her school. Even in games, like the popular VRMMORPG game Satisfy, he's a total loser.
But one day, while on a quest, he miraculously finds a Legendary Book that can give anyone who reads it the never-before-seen Legendary Class! He was planning to sell it for a lot of money but luck was always his worst trait. Through an unlucky change of the situation, his dream was short-lived as he was forced to use the item for himself. His life changed forever since that fateful day.