During the time of chaos amongst the shinobi tribes of no nation, a small but powerful clan called the low mountain sides and vast valleys in the far northen parts of what would become the land of Earth home. They were known as the Tenka clan. Controlling these lands with a unique kekkei genkai, known as Nensho. These experts in the devastating art of explosive chakra may not have been able to match the population might of most other clans, they very much so did in shinobi prowess.
Another unique trait the Tenka are known for is in the odd reproduction habits amongst its memebers. All blood Tenka, whether female or male; no matter the partner produce twins. this pattern formed a tradition that each member may only procreate once a life time to control population within the clan. This was also a double edge sword for it would also put a restriction on population, but at the same time making it possible to manage population. The clan couldnt possibly mantain supplies with a wild population producing at will in double the numbers.
When the shinobi clans of the world began to unite, doubling and trippling their numbers over night and waging massive campaigns accross the lands; the Tenka stood no match. Their homes and resources in danger. After the first battle to defend their homes, one eighth of the Tenka population perished. Without the numbers they would not survive long, but there was an option. The inner circle knew of the whereabouts of the demon known as Gisei, the Owl demon of sacrafice.
Meeting with Gisei at the top of the highest peak, they prayed. Gisei delivered them the power they prayed for in order to save the clan; at a price. Gisei granted them and their descendants for generations to come enormous amounts of chakra, in return for the ritual sacrafice of one of every twin born. For this made sense, Nensho required large amounts of chakra to be at its most effective. In order to match the power of more populated clans, the Tenka can now face four to one odds with much needed ease and survive each battle. After securing their lands, the clans that would become the hidden Stone village invited the Tenka to join their ranks.