Board Thread:Naruto Discussions/@comment-3279282-20140828133937/@comment-24519434-20140829023840

Marc Zaddy wrote: I'm not going to argue this with you any longer, just look at this very wiki to learn the truth. "At some point in the past, Isobu, who was in the possession of Kirigakure, was sealed within a kidnapped Rin Nohara of Konohagakure. They plotted for Rin to be taken back to her village as a Trojan horse, releasing the tailed beast to wreak havoc in Konoha. This failed, however, as Rin was fully aware of their schemes and opted to kill herself at hands of Kakashi before their objectives could come to fruition. Eventually, Isobu was revived and sealed within its next jinchūriki — Yagura, the Fourth Mizukage. However, when Akatsuki went after it, the beast was in the wild; the story behind how it came to be like this is still unknown."

from the wiki, Rin was first. Discussion OVER!!!