One Piece Adventurer's Memoirs of the Seven Waters

In an unknown year A man in a pawn shop wanted to pawn a book The book is called "Memoirs of an Adventurer" The shop owner turned to the first page... The story begins—— Five years ago, an adventurer from the Grand Line came to the Water City. This man has silver hair and a pair of amethyst eyes Opened a coffee shop next to the street.... Intention: When will I know your story?