After 30 years of speculation, Dragon Ball creator Akira Toriyama finally revealed the identity of Goku's mother in the March 2014 issue of Saikyo Jump.
The name of Goku's mom is Gine, a gentle nature Saiyan and part of Bardock's squad. After being saved by Bardock on the battlefield several times they start to develop feelings for each other. This type of sentimentality is rare for Saiyans, who normally don't develop such relationships except when breeding.
Gine will first make her appearance in a bonus manga packaged together with Toriyama's one-shost manga titled "Jaco the Galactic Patrolman", which will be released in a volume on April 4th.
As discussed in the Kanzenshuu.com forums, Akira Toriyama provides a short explanation of Gine’s back story in the article.
He says that unlike other Saiyans, Gine has a gentle nature that is unfit for war. She is part of Bardock’s squad, and after being saved by Bardock on the battlefield several times they start to develop feelings for eachother. This type of sentimentality is rare for Saiyans, who normally don’t develop such relationships except when breeding.
Here is the exact quote of Toriyama, courtesy of Kanzenshuu.
“As for her appearance and such, you’ll find out if you read the bonus comic in the collected release of Jaco the Galactic Patrolman. Her name was Gine, and a long time ago, she fought on a four-person team together with Bardock.
Gine had a gentle personality and wasn’t cut out as a warrior, being repeatedly saved from danger by Bardock. At that time, a special emotion was born between them. Normally, Saiyans don’t have much of a notion of romance or marriage, and apart from the royal family of Vegeta, they aren’t particular about blood-relationships. Being in among all that, I suppose you could say that the pair of Bardock and Gine were those rare Saiyans who were joined by a bond other than for the purpose of reproduction. Incidentally, Gine, who was not cut out as a warrior, would go on to work at the meat distribution center on Planet Vegeta.”
So there you have it!
Goku’s mother will appear in a bonus manga packaged together with Toriyama’s one-shot manga titled Jaco the Galactic Patrolman when it is released in a tankobon print collection on April 4.
It took 30 years for Goku’s mother to finally be revealed!! 1984 to 2014.