Wicked Lord, Let Me Go

Heroine: I grew up an orphan and never knew warmth. He gave me that precious warmth, so I'm willing to do anything for you. I love you more than myself.

Hero: Your feelings moved me, and I fell for you completely. I'd give you everything I have.

This is the story of a heroine who transmigrates to an unknown continent because of the hero, setting off a chain of events. The novel features both the hero and heroine losing their memories, but they still have a sweet relationship, with no major angst. There are only a few minor misunderstandings, along with a System and interstellar elements. The heroine rises from the lowest level, climbing higher step by step through countless hardships, all to destroy the world. Why would she do that? Come read and find out.