Kakashi Chronicles ~ Boys' Life on the Battlefield ~ Part 1

Around 17 years ago, during the Third Great Ninja War, the future Fourth Hokage, Minato Namikaze, assigns 13 year old Kakashi Hatake, Obito Uchiha, and Rin, a medical ninja, on a mission to destroy Kannabi Bridge. As they head off, Kakashi unveils his new Jutsu: Chidori, which Minato notes is incomplete. That night, Minato tells Obito about how Kakashi's father committed suicide after being disgraced. The next day, Minato leaves and Rin is later kidnapped. Kakashi refuses to save her, but Obito ignores him and heads off on his own.