One Piece: My Brother Is Garp, and I'm Taking Him on the Path to Immortality

Modern-day office drone Li Xuan works himself to death in overtime. When he opens his eyes, he has transmigrated to a village in the East Blue in the world of Pirate King. Battered and lying in a thatched hut, he comes face-to-face with a rambunctious little boy. He learns that the boy is three-year-old Garp and that he himself is Garp's older brother by three years. He is completely dumbfounded.