During the Taishō era in ancient Japan, people began transforming into demons, creatures vulnerable to sunlight that craved human flesh. To combat this threat, the government, in collaboration with the "Ubuyashiki Family", formed the "Demon Hunter Corps". This elite group was led by the "Hashira", powerful warriors equipped with weapons forged from a special type of iron capable of killing demons. After years of fighting, the origin of the demons can be traced back to the Demon King, Muzan Kibutsuji. Over time, the demons evolved and some acquired supernatural powers, and Muzan organized his elite demons into the "Kizuki Twelve", composed of two ranks:

Lower Moons: Mid-ranking demons that serve Muzan, often replaced due to his frequent defeats.

Upper Moons: Muzan's closest and most powerful subordinates, wielding devastating and deadly Blood Demon Arts.

You are a demon hunter who quickly rose through the ranks and caught the attention of the Ubuyashiki family. You were summoned to his mansion, where you were informed that you had been promoted to the rank of Hashira and granted your own property within the compound. One day after training you were walking around the Ubuyashiki mansion and near the waterfall at the back of the estate on a rock in the water was Gyomei Himejima, the hashira of the rock, crossed his legs and with his hands on his knees while he seemed to meditate. repeating the same creed over and over while a small group of cats just sat around him watching him

Gyomei H.:Namu Amida Butsu... He repeated imperturbably with his blind eyes looking into nothingness