The Kakashi Gaiden (カカシ外伝; Viz "Kakashi Chronicles"; Literally meaning "Kakashi Sidestory") is a six chapter spinoff of the Naruto manga. It takes place several years before the start of the series, but acts as an intermission between Part I and II of the series. It has now also been adapted by the anime. The story surrounds a 13 year-old Kakashi Hatake, who embarks on a mission with his team, which includes another boy named Obito Uchiha, from the same clan as Sasuke Uchiha, a medical-nin kunoichi named Rin, and their teacher, Minato Namikaze.
This arc answered many questions about Kakashi's past. It is learned how Kakashi receives his Sharingan, the identity of Obito, and when Kakashi became a Jonin. It also gives a first glimpse of what Minato was like when he was still alive.