One Piece : Dark Swordsman

After Monkey D. Luffy became the king of pirates and Roronoa Zoro became the greatest swordsman in the world

The two companions separate, and each goes to live the last rest of his life

Meanwhile, Zoro meets a little boy

As he asks him to teach him how to use the sword in order to become a strong and well-known swordsman

And this is where the suspense begins