Calix is the personal knight of the princess who's going to get the heir of the Yokelm Kingdom; that's why she needed a personal knight, Calix. They eventually fell in love with each other over the years, and he knew it was impossible. That's why he rejected her when she confessed. It's been a few years, and Nishi finally found a guy that would treat her right. Calix was sad that Nishi was going to marry a prince, but he couldn't do anything about it except support her, but he couldn't take it.