“Kage” is set in Japan during the Edo period: Peace reigns throughout the country for the most part. Nevertheless, ninjas are increasingly used to maintain this peace. Karyuu is one of those ninjas – trained and forced to serve as an assassin. She is now asked to carry out a new mission: the assassination of a merchant.

When she arrives at the merchant’s house a short time later, she discovers that the merchant’s servant is also a trained and very talented ninja named Uzume. A bloody battle for life and death breaks out between the two, which both rivals want to win at all costs in order to prove the superiority of their own ninja skills. But who will be victorious?