Dragon Ball Z is the title of the anime adaptation of the second portion of the immensely popular Dragon Ball manga written and drawn by Akira Toriyama, making it the sequel to the Dragon Ball anime. The 'Z' was originally added to the title by Toriyama for the anime, to signify it as being the ending portion of the Dragon Ball series. This series follows the adventures of the adult version of Goku with his companions to defend the Earth and many other planets against various villains. In the original Dragon Ball anime followed Goku through childhood into adulthood. Here Dragon Ball Z is a continuation of his adulthood life but at the same time parallels the maturation of his son, Gohan and to a lesser extent, with his second son Goten.