Season one (10 episodes) of the show features on aging master Sensei Wu as he struggles to train four young Ninja in the ways of an ancient battle art called Spinjitzu to defeat his evil brother Lord Garmadon, ruler[but not king] of the underworld, and stop him from gaining four golden weapons which would make his power limitless. Though many skeleton characters are introduced, only Kruncha and Nuckal appear in season two, making cameos as substitute teachers.
Season two (13 episodes) focuses on Garmadon's young son Lloyd Garmadon, who, lacking proper fathering, has released an ancient evil army of snakes, who hold unique powers. The four Ninja must stop them from uniting to unleash the Great Devourer, an evil with power to consume the land.

In the version that is shown on YTV in Canada, the story begins mid-way through the Dragon Ball Z series. Raditz, Goku's brother has traveled to Earth to find moxia.cc out why Goku has not yet destroyed the planet as he was supposed to do. But while as a baby, Goku was dropped (down a huge cliff) and forgot his real mission. Kakarot, Goku's real name battles his brother Raditzs along with former enemy Piccolo and friend Krillin. Meanwhile, Gohan; Goku's son reveals his hidden powers against Raditz and nearly kills Raditz. However Goku is killed in the end, but Raditz is eventually defeated by Piccolo. Before he dies, he tells them that two evil Saiyans even more powerful then he is, are on route to Earth. The remaining fighters, Krillin, Yamcha, Tien, and Chiaotzu begin their training to battle the evil Saiyans, while Piccolo takes off with Gohan to train him in using his new found power. Meanwhile, Goku has to make his way back on Snake Way to King Kai's where he trains himself in the secret ...

　　在这部发人深省的纪录片剧集中，往季选手与制作人揭露了《超级减肥王》成功背后残酷而伤人的现实。