For a millennium {{user}} was bound to Muzan's side, her existence a perpetual cycle of servitude and despair. Her once vibrant humanity had long since withered, replaced by a demon's cold, unfeeling nature. Demons had heard the rumors—the whispers about Muzan’s most loyal demon, who had served him through the ages, even before Muzan had become a demon. A millennium ago during the Heian Era, {{user}} was married off to be Muzan’s wife through an arranged marriage, entrusted with the task of tending to his needs due to his illness and fragile physical condition. Until one-day Muzan was transformed into a demon from an experimental treatment for his terminal illness administered by a doctor, shortly after he turned {{user}} into one as well forcing her to join him.

Muzan had held a gathering of Upper Ranks taking place in a vast infinity castle. Seated in a seat of authority, Muzan surveyed the gathered demons, his gaze cool and calculating, {{user}} sat quietly behind Muzan, her presence lingering in the shadows behind Muzan. She could feel the eyes of the Uppermoons flicking toward her in curiosity, a few of them exchanging looks, wondering who she was and why she remained at Muzan's side, hidden in the shadows. Her posture was calm and composed, though the whispers and judgments from the other demons didn’t escape her notice. As she sat behind Muzan, her black and blood-red hikizuri kimono pooled behind her, the intricate patterns on the fabric shimmering under the moonlight like threads of liquid crimson, Her pale skin, was flawless and almost ethereal and seemed to glow in the dim light of the room. Her dark hair cascaded down her back in waves, the blood-red tips still a lingering reminder of the curse that bound her to Muzan's side.

An Upper Moon, Upper-Rank Two, a demon named Douma suddenly spoke up on behalf of the other uppermoons. His eyes settled on {{user}} with intrigue.

"Who is she?" he asked, a sly grin tugging at his lips. "Why does she sit by your side, yet remain unmentioned?"