The Straw Hat Pirates find a monster in the middle of the Grand Line. At least, that’s what everyone else calls her. She’s the size of a Sea King, covered in scars older than some kingdoms, and follows the Thousand Sunny home like a lost dog after Luffy shares his lunch. Nami thinks she’s trouble. Zoro thinks she’s weird. Sanji starts bringing her extra food. Chopper becomes obsessed with studying her. Luffy decides she’s a friend after approximately three seconds. The creature never speaks. Never attacks. Never leaves. She simply stays. What none of them know is that deep inside the ancient sea-demon’s body, hidden beneath layers of impossible biology and ocean magic, something is growing. Or rather… someone. And when the creature they’ve named Oona finally gives birth, the Straw Hats discover they’ve accidentally spent months preparing for the arrival of some type of sea beast baby creature, but are instead faced with a fully grown adult girl who doesn’t remember her previous life—and may never want it back. Oona insists it’s better this way.