OK, how can I make this simple... Goten is the second son of Goku and his best friend is Trunks. Goten's coming is rather confusing and hard to explain.When Goku died of a virus before Android #17 and #18 took over control of the world along with Cell, it prevented the birth of Goten, so at the time Goten didn't even exist. But when Mirai Trunks used the time machine Hope to go back in time and save Goku by giving an antidote that would prevent the future coming virus, Goten was able to be born. Goku died again though in the Cell Saga. Now what is that, the 1056 time Goku has died? lol. Mirai Trunks came back in time again to help defeat Cell (this is where Gohan goes SSJ2, tight!) So, since Goten is born, you would think Chi Chi would want another scholar in the house like Gohan right? Wrong, Chi Chi lets Goten train and fight. In fact, she trains HIM. Eventually he goes Super Saiyan when he's 7. He does this in front of Gohan and the look on Gohan's face is priceless. It is around this time that Goten meets Trunks and they become friends. The weird thing about Goten and Trunks is that while being best friends, they are tough rivals in the ring (a little bit of the Lone Star Showdown, eh?). Goten is mostly dragged into things by Trunks that get them both in trouble. Goten is mostly the one forced to do the work that he knows will get them both busted, and it usually does. Later in the Buu Saga, Trunks and Goten fuze together to create the cocky, hard-headed Gotenks. When you watch Gotenks, do you ever say to yourself when he makes a bad decision, "Boy, what a freakin' idiot!" lol Goten turns 17 at the end of DBZ and is 27 during Gt, but iv'e never seen GT so don't expect stuff 'bout it.