Datte Nozomarenai Tsugai desu kara

Adeline, the daughter of an earl, was proposed to by the Dragonkin Realm to become the Mate of the third prince. All Dragonkins must find a Mate and live with them in a castle located on a floating island, despite differing lifespans. She was weak and faced constant criticism from those in the castle, including the prince, who seemed to despise her. Eventually, she was poisoned and died. Two hundred and fifty years later, she is reborn into the same world and once again receives an invitation from the Dragonkin for a ball to find a Mate. She attempts to escape, unaware of a hidden truth behind the invitation.