Saiyan Saga

Goku discovers his Saiyan heritage when Raditz arrives, leading to an epic battle against Vegeta and Nappa that redefines the series' power scale.

The Saiyan Saga is Dragon Ball Z's opening act — the arc that transforms the sunny adventure of Dragon Ball into a harder, more dangerous story by revealing that the world Goku inhabits is far larger and more lethal than the Tournament arcs ever suggested. Five years after the 23rd World Martial Arts Tournament, Goku has settled into domestic life with his wife Chi-Chi and young son Gohan. Then Raditz arrives — a Saiyan warrior and Goku's biological brother — revealing that Goku is not an Earth-born hero but a Saiyan infant sent to conquer the planet. Raditz kidnaps Gohan, forcing Goku and his eternal rival Piccolo into an unprecedented alliance. Goku's sacrifice to defeat Raditz — the first of his deaths in the series — establishes immediately that Dragon Ball Z will not flinch from consequence. The saga's second act follows Earth's defenders training desperately for one year against the arrival of two Saiyan warriors: Nappa and Vegeta, Prince of the Saiyan race. That preparation is not enough. The Battle of Sayians is a war of attrition in which Yamcha, Chiaotzu, Tien, Piccolo, and Kami all fall in defense of Earth. Only Gohan, Krillin, and the eventually-arriving Goku stop the annihilation — and Vegeta, defeated but alive, retreats to fight another day. The Saiyan Saga reframes what Dragon Ball Z will be: a story where the heroes can lose, where allies can die permanently, and where the universe is larger and more dangerous than any previous chapter suggested.