I feel like Ruri is a transmigrator (based on how she talks in Bunny's memories) and Bunny is really the villain. Maybe it's like one of those where Ruri stans the villain and want to protect her so she brought her to the human world and left her in the orphanage when the time was right. As for the parents maybe Bunny only knew them but didn't really met them. Notice how all her memories are only of Ruri?

I cant help but wonder why Bunny was even in the orphanage
What we know about bunny is
-She's a demon
- her parents seem to be the rulers of the demons
- her nanny took her to the humans at a very young age and then left her in an orphanage
But like why. If her parents are dneoj why didnt they raise her, why did Ruri take her when she was a literal toddler and then leave her in an orphanage?
Is she actually related to the ducal house?
Justt agyehdhdb I need more information on why she ended up with humans to begin with. My cute lil baby she's such an adorable chrecter and I have so so so mmay questions!!