Despite their different family backgrounds, four friends grew up together in the wearisome years of the 70s. But as time goes by, each of them takes a different life path.

The memory of their painful breakup still fresh in their minds, two former lovers reunite years later as a top actor and a documentary producer.

Nam Shin is a son from a family who runs a large company. After an unexpected accident, he falls into a coma. His mother Oh Ro-Ra is an authority on brain science and artificial intelligence. She creates an android named Nam Shin III which looks like just like her son Nam Shin. The android pretends to be Nam Shin and he has a bodyguard So-Bong.

Kingdom of Goguryeo, ancient Korea, 645. The ruthless Emperor Taizong of Tang invades the country and leads his armies towards the capital, achieving one victory after another, but on his way is the stronghold of Ansi, protected by General Yang Man-chu, who will do everything possible to stop the invasion, even if his troops are outnumbered by thousands of enemies.