Hahanoai

is a fūinjutsu created by Sorame Uchiha. Implemented on her deathbed, she placed the technique on her eyes after removing them from her sockets. Within the seal, Sora created a link to her chakra by closing the solidifying it with her blood. As a result, it is designed to recognize only her daughter's chakra and signature because of its derivative nature. This is designed as a defense mechanism for when the day comes where Isa implants them into her own eye sockets. Anyone else who attempts to do the same with Sora's eyes are subjected to flames that burns their head from the inside out, the seal doubling as a protector that leaves the eyes unharmed. The only person capable of rewriting the seal signature is Isaka herself, though the format for doing so resides within the pair of eyes, preserved for the child who is next to bear them.