Sandglass (1995)

The plot looks similar
It gives the same vibes of 2 ML's as one becomes a Gangster & other job is a public servant.

Similar era (gangster and politician join hand in hand, the importance of constructor), very similar background music (was it even the same?), similar style of presentation, lastly they tackle similar theme (injustice, rich people do bad things because they're bad while poor people do bad things because they have to) in a similar way

Same director and writer. The 2nd lead in Sandglass is the same actor as the main in Eyes of Dawn. There is also a lot of actor sharing in the casting.

Also has a backdrop of real events and is a romantic action melodrama with similar themes of loyalty and righteousness.

Both were portraying tumultuous decades of South Korean history. A bit different approach but seeing the same object of history.