One Piece: I, Luo, Roger’s Son, the Marine Admiral!

Seven years after transmigrating to the world of Pirate King, the unremarkable Ige thought he could just coast through life. But three days ago, he learned that he was the twin son of the late Pirate King, Roger! Ace was his big brother, the old man who had been taking care of him was Dragon, and that meant he had to call Garp Grandpa! Ige was utterly stunned. “Ding! Congratulations, Host, you have obtained the Myriad Worlds Check-In System!” “Ding! Check-in successful. Reward: Sand-Sand Fruit ability, LV6!” “Ding! Check-in successful. Reward: Supreme Swordsmanship, LV5!” “Ding! Check-in successful. Reward: Rumble-Rumble Fruit ability, LV6!” ... As he checks in every day, Ige becomes a Marine Admiral!