Finally naruto 502 has been released.

Uchiha Madara exploit the weaknesses of naruto mother pregnancy and summoned the nine tails. In this naruto 502 chapter The fourth hokage goes to war. Nine tails summoned by Uchiha Madara. The fourth hokage Minato fight with Uchiha Madara. Both of them can use  the teleport stance. At the end of Naruto 502 Uchiha Madara Minato knocked using Rasengan ultimate stance.In this chapter you can see the young kakashi and gai sensei. And you could see the fifth hokage uses armor to figth the nine tail.

You can read naruto 502 manga here

http://mangastream.com/read/naruto/18388702/1