K.O.3an Guo (2009)

It's the first of the series. You understand the story universe and characters better if you start with this one first.

- basically the same plot but a remake
- K.O3an Guo is the older version

this the second installment of KO One series. You will understand the story and characters better if you watch it in order though you could still watch it without it.

In both, the main character had traveled through time and was forced to act as the lookalike imposter of the king from that period. He attempts to unify the kingdoms into one country.

Both series expand on one of the male roles who is in love with his older brother's girlfriend, but gets friendzoned.

Though K.O. takes a (later) crazier approach on school fights and tons of bizarre unbelievable superpowers for the main delinquents, both series are very fun to watch if you love school delinquent fighting for the top ranks!

Both dramas use the comical acting style for lots of laughs.
Both dramas merge an ancient drama with the modern world.
In K.O.3an Guo there are different dimensions and one of the dimensions takes you to a historical past setting.
In Your Highness, they are in a gaming world that is set in a historical setting.
Both dramas include a villain with a hidden identity.