Do Min-joon (Kim Soo-hyun) is an outsider who arrived on Earth in 1609 during the Joseon Administration. He saves a young lady named Website optimization Yi-hwa from tumbling off a precipice and misses his return outing to his home planet and is abandoned on Earth for the following four centuries. He has a close wonderful human appearance, upgraded actual capacities including his vision, hearing and speed, and a negative, tainted perspective on individuals. Min-joon never ages and is compelled to take on another personality like clockwork; he has filled in as a specialist, a cosmologist, a legal counselor, and a financier, and is currently functioning as a school teacher.

Cheon Tune yi (Jun Ji-hyun) is a renowned Hallyu entertainer who achieved fame as a schoolchild; her haughty disposition has procured scorn in media outlets and via online entertainment. Melody yi’s squanderer mother has fumbled her funds and her more youthful sibling Cheon Yoon-jae (Ahn Jae-hyun) is alienated by her prosperity. Lee Hee-kyung (Park Hae-jin) has been Melody yi’s companion since center school and stays in adoration with her however is persistently dismissed. Thus, Yoo Se-mi (Yoo In-na), Tune yi’s lifelong companion who is much of the time cast in a supporting job close by Melody yi has really liked Hee-kyung since center school regardless of her affection being lonely. Subsequently, Se-mi subtly harbors a profound envy towards Tune yi for disrupting the general flow of her vocation and old flame.

With just three months left before Min-joon’s hotly anticipated takeoff to his planet of beginning, Melody yi out of nowhere turns into his nearby neighbor in the condo where he resides. Gradually, Min-joon ends up entrapped in Melody yi’s insane and eccentric circumstances, saving her on various occasions involving his unique powers and in the long run going about as her director because of his tremendous legitimate information. He figures out that she early in life looks like Yi-hwa, with whom he fell head over heels for 400 years sooner. Min-joon and Tune yi in the end fall head over heels; Min-joon means to leave Earth without being sincerely joined so he attempts to keep away from her yet fizzles. While Melody yi at first doesn’t comprehend his approaching flight, she eventually acknowledges allowing him to go to guarantee his endurance.

Tune yi’s vocation goes into a slump when her ability organization and patrons drop her in a reaction against her new way of behaving, especially reports that she caused the self destruction of her most outstanding opponent, entertainer Han Yoo-ra. Prior at a big name wedding, Tune yi had found Yoo-ra was in a mysterious relationship with Lee Jae-kyung (Shin Sung-rok), the senior sibling of Hee-hyung. Jae-kyung attempts to quietness Melody yi until Min-joon representatives an arrangement to save her as a trade-off for covering the proof. Jae-kyung, in any case, ends up being significantly more hazardous than Min-joon thought, figuring out how to take advantage of Min-joon’s shortcomings and harming Se-mi’s more established sibling, an examiner who is exploring Yoo-ra’s self destruction. Min-joon, in spite of being watchful in the utilization of his extraordinary capacities, ultimately draws the consideration of police while failing to keep a grip on his powers as his flight date approaches. While envious of Min-joon for prevailing upon Tune yi, Hee-kyung works with Min-joon to safeguard her from Jae-kyung.