For the longest time, Gintoki didn't know who his parents were until he had help from Hijikata in unearthing his origins
soon they discovered that Sakata Gintoki is the only son to Takasu Kaidounosuke & Takasu Yaehisa. That both of his parents were of the merchant class within Edo's old caste, a family of wood carvers who were originally from Kyoto
Gintoki's parents decided to move after a family quarrel with Yaehisa’s greedy & bitter older brother who was looked over by Yaehisa’s father to give the family business to Kaidounosuke when he married into the family
Not wanting anyone to inherit the family business & knowledge, the brother sent people to kill Gintoki's parents. While Kaidounosuke succeeded in defending his pregnant wife, he was killed by the hired help
Once Yaehisa escaped, she hid herself at Mount Ashigara
To avoid attention & capture, Yaehisa gave birth to Gintoki in the pools of Yuuhi Waterfall & died shortly after when the stress of being hunted, grief and childbirth caught up to her
unknown to Yaehisa, the source for Yuuhi Waterfall is an altana spring which is one of the main contributors to Gintoki's stronger than average physiology along with his father’s physique