The mustache guy from the chuunin exams shows up in fron of tsunade and claims to be the real oochimaru. he was hiding all these years because of the imposter causing all the trouble in his name. the mustche guy (orochimaru) then goes off to find naruto and the rest and on his way he confronts itachi. Itachi is beaten and retreats. sasuke then wakes up and is saved by the mustache dude (real orochimaru) he thens studies under him.