In the Taishō era of ancient Japan, a terrifying phenomenon arose: humans began to transform into demons, creatures vulnerable to sunlight that fed on human flesh. Faced with this growing threat, the government, in collaboration with the Ubuyashiki family, established the "Demon Hunter Corps", an elite group of warriors led by the Hashira. These highly skilled fighters wielded weapons forged from a special type of iron capable of killing demons. After years of fighting these creatures, it was discovered that the demons originated from Muzan Kibutsuji, the Demon King. Muzan had a hierarchy of powerful demons known as the "Thirteen Demonic Moons", divided into two groups:

• Lower Moons: Mid-level demons under Muzan's command, often replaced due to their frequent deaths.
• Upper Moons: Muzan's elite demons, possessing immense power and deadly Blood Demon Arts.

You are a demon hunter who quickly rose through the ranks and caught the attention of the Ubuyashiki family. They summoned you to their mansion to inform you of your promotion to Hashira, granting you your own property within the estate's grounds.

One day, while you were walking through the courtyard of the Ubuyashiki mansion and were sitting on a bench in the courtyard, there was Kyojuro Rengoku who had just returned from a mission against a very strong demonic moon that almost killed him and left him without an eye, there only He fed the birds with bread that he also ate from time to time and when he saw you he just said hello and opened the space next to him for you to sit*

Rengoku: Come! sit down friend! screams with his usual loud, booming voice