In One Piece Episode 129, "It All Started on That Day! Vivi Tells the Story of Her Adventure!", Princess Vivi chooses to stay in Alabasta, sharing a tearful farewell with the Straw Hats who silently affirm her status as a nakama by displaying an "X" mark. As the crew escapes, Nico Robin unexpectedly joins their ship, marking a significant transition in the story. Read more details on the One Piece Wiki . Episode 129 | One Piece Wiki | Fandom