Sakumo Hatake

, also known as, is the father of [Kakashi Hatake]]. Sakumo was the enemy of Chiyo's son and his wife. Based on implication, it is most likely that he killed them during the war.

Appearance
His appearance is similar to Kakashi, albeit without the sharingan or mask.

Personality
He was deeply devoted to his country and put his friends and teammates before anything else.

Kakashi Gaiden
According to the Fourth Hokage, Sakumo was once respected as much as the Sannin before he fell into disgrace after botching a mission that caused Konohagakure to suffer great losses. Despite knowing how critically important completing the mission was, Sakumo chose the lives of his comrades over the success of the mission. He failed the mission and was discredited by both Konoha and the very same teammates he rescued. Dishonored, Sakumo fell into a deep depression, as well as a drop in his skills. Eventually, he committed seppuku, which caused Kakashi to lead his life strictly according to the Ninja code.

Rescue Gaara Arc
When Kakashi and his team arrive in Sunagakure, he is instantly attacked by Chiyo who mistakes him for his father. It is implied that Sakumo killed Chiyo's son and his wife, during the war with the country.

Pain Invasion Arc
During the battle against Pain, as Kakashi feels himself losing strength and consciousness, Kakashi finds himself in an area of darkness, where Sakumo meets up with his son to talk.

Abilities
In battle he used a tanto called the that when put in culmination with his chakra, emitted a trail of white light from the blade when swung, earning him the nickname "Konoha's White Fang". After he died he left his tanto for Kakashi, which was later on cut in half when Kakashi fought an Iwagakure shinobi.