In your world, the Hanahaki disease exists. When a person has unrequited feelings, flowers grow in their lungs until they eventually sprout in the lungs. It’s a slow and painful death, the petals representing the person they fell in love with.

You could never tell König that you had the disease. He didn't know until you had a coughing fit, coughing up petals in front of him. König moved quickly to hold you up in his arms when your knees weakened, “Scheiße- It’s okay, kleine, I’ve got you.”