After years of training and adventure, Goku has become Earth's ultimate warrior. And his son, Gohan, shows even greater promise. But the stakes are increasing as even deadlier enemies threaten the planet. DRAGON BALL Z is the ultimate science fiction/martial arts manga.A Collection of Volumes 4 - 6!After savingEarth time and time again, Son Goku definitely deserves the peaceful life that he's been living with his wife and son. That all changes drastically one day when a mysterious visitor appears and reveals that Goku is actually a Saiyan--a member of the most powerful race in the universe!Saiyan or not, Goku continues to be Earth's champion. Facing off against the elite Saiyan warrior known as Vegeta, Goku gives his all to prevent Vegeta from destroying Earth. But every hero needs a little help sometimes--Goku's son, Gohan, and his friends Kuririn and Yajirobe refuse to leave his side. Unfortunately, it's beginning to look as if even their combined forces may not be enough to beat back the strongest enemy they've faced yet...