Romantic comedies with the same feel and both starring Gong Hyo Jin!

Written by the same writer, both have similar storylines--a princess is locked up and the main actor is the one who brings the princess out. The main actors in both dramas go under a codename: Joo won uses the name "Yong Pal" and Ji Chang wook uses the name "K2." Both are action-packed with a dash of romance.