Uriae Daehan

The 21st-century Korean Empire, where absolute monarchy persists. After the Crown Prince and Princess were assassinated, the royal family concealed the princess's existence completely. Then, thirteen years later, a transfer student named Do-Yeong appears before ordinary high schooler Hyeon-U, claiming to be the princess. Is Do-Yeong truly the princess? Or is this yet another deception?
The royal family, the resistance, and the hidden heir. The truth surrounding the throne begins to unfold.

(Source: Naver, translated)