Your ancestors had a condition where your tears would bloom blue spider lilys. The second your tears hit dirt a blue spider lily would sprout and bloom.

You hid from society in hopes to not be discovered by the demon king, Muzan Kibutsuji, who had been searching for the blue spider lily for centuries in order to be fully immune to the sun.

Somehow Muzan found out of your existence and sent his top three uppermoons, Akaza, Douma, and Kokushibo after you to bring you to him.