Goku struggles against the overwhelming gravity and mistakes King Kai's pet monkey, Bubbles, for King Kai. He then meets the real King Kai, who tells him a couple jokes much to Goku's bewilderment. The poor reaction causes King Kai to tell Goku that he won't train anyone who has no sense of humor, so he has one condition before he will train Goku: he must think of a joke that will make him laugh. Goku gives it his all and create several weak puns that amuse King Kai immensely.
Goku tells his new mentor about the Saiyans who King Kai tracks down, and tells Goku that they will arrive in 158 days and are even stronger than himself. King Kai begins Goku's training and gives him his first task: to catch Bubbles in the 10-G gravity of King Kai's World. Goku removes his weighted clothing and strenuously chases Bubbles but stops when he realizes how hungry he is. King Kai feeds Goku then tells him to put his weighted clothing back on as it will benefit his training. He then tells Goku that the reasons the Saiyans are so strong is because their planet has the same gravity as the planet they are on.
Back on Earth, Piccolo continues to train Gohan who notes his improvement but says he still has a long way to go. At night the two sit around a fire with Gohan telling Piccolo that he's now become part of his family, a "big green uncle". Piccolo, annoyed by the affection, tells Gohan to sleep because his training will be even harsher tomorrow.
After three weeks, Goku finally manages to catch Bubbles. Impressed that Goku has managed to overcome his planet's ten-fold gravity, King Kai anticipates that Goku may be able to master the powerful "Kaio-ken" technique.
- The title of this episode is a direct translation of its Japanese title.
- Starting with this episode, every title card in the Saban dub would have the same music. Prior to this episode the music for the title card varied from episode to episode.