The caste game sort of reminds me of the Standford Prison Experiment where university students were told they could either be guards (with all the power) or prisoners (who must follow orders) for credit in a psychology class. Very soon, some of the guards started bullying and abusing the prisoners, even though they knew it was just an "experiment" for class. Other guards were not as bad, but they did nothing to stop the bullies. The professor had to shut it down when some prisoners had breakdowns. Some had permanent psychological damage.
This manga turns such an experiment on its ear, because some of those who have power decided to play a Prince and the Pauper/Trading Places game with the king and the target. Oh, and they each have their own little agenda sexually too. So now it's not only about how people wear masks and play roles and abuse power, it's also about how people react to shifts in power (and about a personal "relationship" of sorts between seme and uke).
At first, I really loved this manga. Now I hate it yet I can't stop reading it. I really don't know what to feel... Like really, what the heck is happening... (⊙…⊙ ) I used to love Kuze, now I no longer know what to think about him... I need the next chapter... ┗( T﹏T )┛