My Love from Another Star movie plot

The alien who fell in North Korea 400 years ago, with his 4 centuries of secrets, lives alone under the sky of Seoul. Still possessing the same youthful and handsome appearance as when he first arrived on Earth, and possessing super-genius abilities, he is Do Min Joon, a current university lecturer . On the other hand is Cheon Song-Yia brash Hallyu star . The adjacent men and women burst out with sparks, discovering the ties related to the previous life. Do Min Joon, who is three months away from returning to his own planet, accidentally fell in love with Hallyu star Cheon Song-Yi   .