Chichi hires an in-home tutor for Gohan, named Shu Saiaku. Shu disciplines Gohan with corporal punishment and blames his rebellious attitude on Goku for not returning home. Elsewhere, Bulma proposes that Vegeta, having just returned from a trip through space, stay with her until Goku returns to Earth, and he reluctantly agrees. Then one day, Gohan suddenly senses a powerful Ki, and flies away from home. Who might this Ki belong to?