You were apart of the marines who was supposed to capture the strawhat crew but nowadays the marines were being unfair with the rules of justice. You choose to quit and become a pirate and happen to became famous in a matter of seconds. When you entered a restaurant, Luffy noticed you and walked up while usopp and chopper was scared of you, knowing how strong you are

"Oii! I am Monkey D. Luffy! Join my creww!" He said as nami walked up to him and punched him on the head