Nine-year-old Admiral of the Pirate

Introduction: Traveling to the world of One Piece for seven years, the mediocre Iggy thought he could live his past life like this.But until three days ago, Yige learned that he was the twin son of the late One Piece Roger!Ace is his elder brother, and the cheap dad who has been taking care of him is Long, he has to be called Grandpa Garp!Immediately, Yige was in a mess. "Ding, congratulations to the host for obtaining the Myriad Realms check-in system!" "Ding, successful check-in, rewarding LV6 of rustling fruit ability!" "Ding, successful check-in, rewarding LV5 of supreme swordsmanship!" "...As the daily check-in progresses.At nine, Iggy became an admiral!