With Killer Bee as his new master, Naruto begins his training to control the power of a Tailed Beast. In order to do so, one must fight the Tailed Beast head on and absorb its chakra, converting it into one’s own power.
It is the key left by
the Fourth Hokage
المفتاح الذي تركه الهوكاغي الرابع
Esta es la llave del sello 
que dejó el cuarto Hokage.
Esta es la llave del sello 
que dejó el cuarto Hokage.
La chiave lasciata dal Quarto Hokage
 che apre e chiude il sigillo sul tuo ventre.
É a chave deixada pelo Quarto Hokage
Ключ от четвёртого Хокаге, который
работает с печатью на твоём животе.