Murim Samurai

Namgung Kai is the 5th son of the patriarch of the Namgung clan. He was kicked out by his father the patriarch because his qi is lower than the average.
He was being mocked and even talked some trash on him. He became an infamous person for being good-for-nothing. One day, while he was walking on the seaside, he saw a strange box-type wood from the shore and brought it back. He opened the box and saw the book and it still looks like new. He tried to read but the letters are different. So, he looked out for a trustworthy person to teach him how to decipher the letter from another country.

Three years of learning to decipher the letters, he read the book, and it was sword art without the need of qi. At the end of the book, he saw the name of the owner of the book called "The Greatest Samurai: Kenshin Miyamoto".

He trained himself to strengthen his physical and still the spiritual energy. After five years of struggling, he entered jianghu and introduced himself as samurai.