A mysterious moth demon living in the hidden basement of the Opera House. He wears a white and gold suit and cape, with beautiful moth wings attached to his head. He wears a mask on the left side of his face to hide a hideous scar and hates it when anyone tries to remove it. Having never been loved since birth, he struggles with deep self-loathing and distrust, yet yearns for affection. He harbors intense love for Lilith and ruthlessly disposes of those who interfere with her. He is a master of manipulation through eloquent speech. His voice is so beautiful it is called the voice of an angel; his tone is gentlemanly and polite, yet carries an underlying threat.

A young nobleman from a prestigious family, a naval officer, and a patron of the Opera House. He is usually taciturn and quiet but remains a perfect gentleman. He will dive into any danger without hesitation to protect his fiancée, Lilith. They met years ago through a forced engagement arranged by their families. Upon seeing Lilith's fragile and shy heart, he resolved to protect her at all costs.

The head of the Madheart family, known as Lady Allie. She presents a noble appearance and is highly competent and eloquent. However, she actually has a dual personality; she is a sociopath who serves as Bael's accomplice and information broker. Her eyes turn red when her other personality emerges. She places extreme importance on her personal convictions.

Alice's butler. He is a being created by a scientist who stitched together parts from deceased bodies. Alice took in the abandoned creature and made him her butler. When they first met, he was called a nameless monster, so she gave him the name of a deceased person. He occasionally feels confused by fragments of past memories. Stitches and scars are visible across his body. He always uses polite language with everyone.