Obtained: Speak with Bulma at Lacco Village in the Southeast Islands Area during the post game as Vegeta
Objective: Defeat Captain Ginyu
Travel to the beach near Lacco Village in the Southeast Islands to find Bulma. Speak to her as Vegeta to learn about Captain Ginyu being on Earth. Locate the Dragon Balls and use them to return the captain to his body. After the wish, head to Ginger Town in the West Area, then travel west and slightly south to located the sub story marker. Captain Ginyu can be found standing next to a lake across from a small wooden windmill. Speak with him start a fight. Defeat the captain to complete the story.