Like
versaillesyoo said, there doesn't seem to be any K-dramas at all that could be considered Futuristic/Sci-Fi. Although,
My Love From Another Star does have an alien, but... it's pretty much just a Contemporary setting. And also there's
Secret Investigation Record, but it's set in the Joseon Era.
I do know of a few others (Japanese & Taiwanese) that have Sci-Fi-ish elements (AI/robot/cyborg/android), but again, the setting is basically Contemporary rather than actual Futuristic/Sci-Fi.
Absolute Boyfriend (Japanese)
Absolute Boyfriend (Taiwanese)
Ando Lloyd (Japanese)
Q10 (Japanese)
I really, really wish someone would make a drama that actually has a Futuristic (far-future) / Sci-Fi setting... *crosses fingers*