Dragon Ball Kai • S07E45 : Headlong Rush into Catastrophe! A One-Hour Time Limit!
Piccolo's hopes of being able to buy some time are dashed when Evil Buu unleashes a powerful homing attack which targets and kills every human on the earth, with the exception of Mr. Satan, Tien, and Chiaotzu. Piccolo, along with Videl, manages to convince Evil Buu to wait for an hour so that Goten and Trunks can train. Meanwhile, Gohan, tired of waiting any longer for Old Kai's power-up, discovers that he has indeed managed to increase his power and agrees to wait for the power-up to be completed.