Both dramas have a king who travels to the present and later also to the past. Both romantic comedies.
Both dramas have the female lead travel to an ancient parallel universe. I think the vibes of the two dramas are also similar. The female leads also have a bubbly character (Though Xiao Tan is definitely more sassy) and the male leads are portrayed more cold on the outside but warm on the inside.
Both dramas have characters who time-travel to the past. The difference is that in Somehow 18, the main character had a purpose for time-traveling and in Love, Timeless the time-travel is an accident that the main character happily accepted.
They've got the same main actor. Both shows give a similar vibe. The K2 has less comedy tho.
