Romance dramas are often part and parcel of any K-drama enthusiast's watchlist, but what if you want something grittier?

We've been spoiled for choices in recent months with darker shows — from A Shop for Killers, which follows the young niece (Kim Hye-jun) of a retired mercenary (Lee Dong-wook) in the weapons trade who tries to escape an assassination, to Vigilante, which follows a star police academy student (Nam Joo-hyuk) by day and titular vigilante by night.