Aria proposed a contract marriage.
To the young Grand duke Valentine, who had sold his soul to a demon.
To protect herself, and to protect him.

"Marry me."

With hands as delicate as autumn leaves, Aria extended the marriage vows along with a note.

"Since it’s a contract marriage... we can divorce 10 years..."

But the young Grand Duke snatched the note from her and tore it to pieces, saying,

"So... where do I put my seal?"

"You said we could divorce when we were grown."

Before she knew it, the demon Grand duke, now grown, leaned over her forehead and pressed his lips to it solemnly,

"Now that we’re adults, it’s time to make an adult’s contract."