I know I often change my mind :). But I'm going to change Nana's story. Nana is now no longer Sakura's sister, but her cousin. Her father is the big brother of Sakura's mother and Nana's mother comes from Yuukigakure and dominates the Kekkei Genkai ice. Therefore, it also dominates Nana :). She lived with her mother in Yuukigakure till she died. And now she lives with her ​​father in Kohoha and thus meets her cousin.