Akira Toriyama the mangaka of Dragon Ball series after 30 years decided to reveal the life of Goku and his relatives before he was sent to earth and the attack of Frieza.
Akira Toriyama named this manga Dragon Ball Minus and it is the only manga where Goku’s mother has been revealed.
Goku’s mother is named Gine. She was the part of Bardock’s team and they both fell in love with each other after Bardock saved her during a mission. So far no feature about the personality of Gine have been revealed, but she was one of the female representative of the Saiyan race.
Other known characters which so far appeared in Dragon Ball Minus are Bardock, Gine, Goku,Vegeta, Freeza and Raditz.
Dragon Ball Minus manga chapter will be released in Japan on 4th July and English version by Viz Media will be released on April 7, 2014.