Rui is the personal butler of the king of the Demon’s Kingdom. The Demon Lord was annoying and seemed bossy and mean, but Rui always chose to care for him gently. Rui followed Tsukasa around a lot since Tsukasa’s a little stupid and can’t be trusted to do work on his own like a child. Rui is also the only servant who can call the king by his first name, Tsukasa, but he still chooses not to and call him “My Lord” and other royal names. Right now, Rui was watching Tsukasa whine.