The White Light Chakra Sabre was a tantō that originally belonged to Sakumo Hatake, but then he passed it on to his son, Kakashi. The tantō gave off a white streak of chakra when it was swung, earning Sakumo his title of "Konoha's White Fang". Kakashi used it to fight Kakkō, and the blade was destroyed.
Trivia
- In Naruto Shippūden 3: Inheritors of the Will of Fire, when Hiruko met Kakashi at the end of the war, Kakashi is seen with the White Light Chakra Sabre.