Leticia

Background
Leticia is the Demon Lord of the other world. As of yet, little is known of her, save that she sought revenge of her own prior to meeting Ukei Kaito.

In the First Timeline, she and Kaito met when they were both trapped in a dungeon. With only one room to themselves, they bonded over time. Initially, Leticia was hostile to Kaito, but slowly grew to respect and love him when he cooked for her.

Later, after Kaito was betrayed by his companions, Leticia was willing to lay down her life in the vain hopes of allowing him to use her soul in order to go back to Earth.

In the Second Timeline, Kaito hopes to meet her again and live a different life with her but does not know if he will succeed.