I'm Garp's Granddaughter's Husband and Luffy's Younger Sister's Brother-in-Law

I, Mag, transmigrated and, for some inexplicable reason, a girl started calling me "sir."

May I ask your name, miss? What?! Monkey D.??

Garp: "If my grandson couldn't do it, then let my granddaughter take his place! Erya, would you be willing to join the Marines?"

Luffy: "Mag has never called me big brother!! But I respect him a lot!"

Mihawk: "What? I can't beat Mag? That's a fact, but if I'd eaten the Sword-Sword Fruit too, the outcome would have been reversed."

Sengoku: "Perhaps... the justice in Mag's heart is the true kind. In centuries, he's the person most likely to overthrow the world! I've always believed that!"

This novel and its characters are entirely fictional. Any resemblance to actual people or events is purely coincidental. Do not imitate.