In this sub story of Dragon Ball Z: Kakarot, Bulma will be on vacation in the southeast islands and won't want to talk to anyone but her husband. As Vegeta, tell her about your quest for power and Bulma will remind you of Captain Ginyu.
The Captain's Comeback
As a reminder, Captain Ginyu transferred himself into the body of a frog by mistake during the Frieza Saga. In this sub story, Vegeta will go in search of the crystal balls in order to give back his appearance to the captain of the Frieza Commando. As usual, on the world map, pay attention to the crystal ball icon at the bottom of each area and then open the radar to find them in any zone.
Once found, open the menu and select the Dragon Balls. You will then be able to select three different wishes, one of which is to restore Captain Ginyu's appearance. Once Sheron is gone, go to Ginger Town, which will be by the lake. Surprised that he's back to his old self, he'll be willing to fight you. The fight goes off smoothly overall, even he's level 75.
When the fight is over, Bulma will arrive by car, wishing to attend the fight that has just finished. Ginyu will try one last time to steal Vegeta's body but Vegeta will convince him to train with his own body and come back when he is stronger.
In addition to the rewards offered at the beginning of the fight, the soul emblem of Captain Ginyu will be yours. It'll be useful for the community training board.