Episode 17: Pan is Born! And Goku Goes Off on a Training Journey!?

Pan has been born. While most of her family members and friends think that she should be taught martial arts, Chi-Chi is revolted by the very idea. She believes that Pan should be raised to be a lady and not a mindless fighter like her grandfather Goku. Everyone tries to persuade Chi-Chi to change her mind but to no avail. Bulma accidentally mentions that Vegeta has been away training with Whis for six months, which shocks Goku. After some time, Whis returns to Earth to enjoy more of the food Earth has to offer. Goku approaches Whis and asks to become his pupil. Whis accepts, thinking it is the perfect time for Goku to join Vegeta in training. Just as the two are about to depart, Chi-Chi runs up and stops Goku from leaving. Despite her wishes, Goku ends up leaving with Whis. Chi-Chi then has a sudden change of heart, saying that Goku will return once he gets hungry anyway. Source: Wikipedia