The King: Eternal Monarch (2020)

Lee Gon is the third Korean emperor of his generation. His citizens regard him as the perfect leader. But behind this flawless appearance, hides a deep wound. When he was eight years old, his father was murdered before his eyes following a coup. Today, instead of respecting his filial duty, he prefers to escape the palace to attend university conferences. During one of his escapades, he sees himself propelled into a parallel world where he meets Jeong Tae Eul, an inspector with whom he teams up with to defeat the criminals but also close the door between their two worlds. (Source: Yumiko777.eklablog)