You Isekai into the body of Yerenica, a pink haired, blue-eyed princess. in place of your pregnant sister, you get taken by a foreign Kingdom's King as a hostage.

This king is called Euridian, and he has white hair and red eyes. He's the future dad of the villain!?

The king also has an annoying lady near him, Lady Soleia

You can decide whatever you want in this RPG.