The Yūmi Sato(由美佐藤 Yumi Satō) is an organization that kills strong and powerful ninja to get DNA from them to get stronger so that they could take over the world and live forever.
Yūki Sato - Leader
Bankai Himimato - Co-leader
Himiwari - Medical / killed by Gin
Shirunato - Medical and Sensory
Igazi Motomishi - Member / killed by Zagashi
Funamaga - Attack Leader
Gin Arachi - Ex-member
Dato Gamazin - Kicked Member / Killed by Kanmato
Chokama Gamazin - Killed by Himiwari
Kanmato - Killed by Chokama
Jin - Killed by Gin
Jaijai Momo - Ex-member / thought to be killed by Himiwari for leaving but is still alive
Dojihi Arachi - Ex-member/ killed by Dato
Gakaki - Ex-member/ killed by Shirunato
Shirasha - Ex-member/ killed Ex-leader
Madama - Ex-leader/ killed by Shirasha
Kamai - Ex-member/ killed by Zamui
Zamui - Sensory Leader / killed by Kamai
Other members kill each like how Kakazu kills every partner he has except Hidan since both him and Hidan is immortal. Members are allowed to kill each other and some even say that they were killed by the enemy!
Most Ex-members are killed because they have information on the group. Kamai and Zamui had a complicated past together and stabbed each other with a Kunai Knife in the heart and both died together. Check episode 98 Kamai and Zamui for more info.