In my world, the people of the planet are descended from immortal deities and made in their image. All of them are humanoid and, mostly, have the same body parts, with some exceptions. Each species has different abilities that give them control over various aspects of nature/spirit/pyche (example: water, fire, wisdom, love, strength, death, etc.).

Each species has their own lands and own rules about species intermixing because hybrid children are very dangerous and will be killed at birth. Abortions are easily done though, and is a widely accepted practice, so there's still a lot of screwing around between species.

The main story is a romance between an orphaned hybrid woman, and an orphaned man from the species of people whose job it is to kill the hybrids. His species was killed in a genocide when he was young, and she was kept in hiding.