Hwarang ; The Return Of The King

Prince Sam Maekjong was named as the king of Silla while he was just seven years old. Therefore in order to protect him from enemies his mother Queen Ji Soo decided to rule the country until the king is ready. The young king were to go hiding with his only guardian Pa-Oh.

Nobody in the country except the queen and his guardian know the king's face and his true identity.

Even after several years the queen is not ready to step down and give away the throne to its rightful owner. The young king who is 21 years now has determined to prove his mother that he is capable of ruling his people despite of the fact that the queen thinks of him as a weakling.

His first step to that goal is becoming a warrior among the queen's Hwarang. Under the fake identity of Kim Ji dwi the young king blends in with the other young Hwarangs and explores his youth, makes friends and falls in love as he reach his goal.

( The story is based on the 2016 KBS2 drama Hwarang. The story is focused on Ji Dwi / Sam Maekjong and his journey to the throne unlike the original script.
I always found his story interesting and obviously his character stole the show )