Source taken from naruto.wikia.com and narutofanon.wikia.com
The History:
The Seven Ninja Swordsmen of the Mist (Kiri no Shinobigatana Nananin Shū) is an organization consisting of only the greatest blade-wielding shinobi of their generation that Kirigakure can produce. There can only be seven members at a time, hence the name. Four members are currently known, although the third, Raiga, only appeared in the anime. Three of them are missing-nin.
The History:
The members of the Seven Ninja Swordsmen were the people who came from the Bloody Mist's graduation exams with the greatest battle skills. However, the members also had a great lust for power. This led many of them to defect and become missing-nin. Kisame Hoshigaki was the first to abandon Kiri, and joined Akatsuki. Zabuza Momochi would later follow him after a failed coup d'etat and assassination attempt on the Mizukage.
