Season 1

Having put up with the much lower intelligence of humans for 400 years, Min-Joon is preparing to return to his planet when he meets actress Song-Yi.

A distraught and drunken Song-Yi barges into Min-Joon's apartment and ends up falling asleep, and it's revealed that the two have a past connection.

Min-Joon has a premonition about Song-Yi, and when he accompanies her to the hospital for an appendix operation, he tries to subtly warn her.

Min-Joon watches over Song-Yi while she attends a party cruise. Meanwhile, we learn more about Min-Joon's connection with a girl he met long ago.

Reporters are camped out in front of Song-Yi's apartment thinking she killed Yura, so she hides out at Min-Joon's and they get better acquainted.

An intense rivalry has developed between Min-Joon and Hwi-Kyung, both of whom are feeling possessive of Song-Yi. Hwi-Kyung professes his love for her.

Song-Yi tells Hwi-Kyung she doesn't return his feelings. Min-Joon gets more attached to Song-Yi despite himself, and she asks him to be her manager.

Min-Joon saves Song-Yi from yet another accident, but he denies being there when she claims she saw him. Jae-Kyung renews his efforts to kill Song-Yi.

After Min-Joon and Song-Yi kiss, his temperature spikes dangerously high and she tends to him. Jae-Kyung's minions suspect Min-Joon has the USB drive.

Hwi-Kyung and Song-Yi both confront Min-Joon about being Song-Yi's rescuer. Song-Yi's finances are falling apart. Jae-Kyung tries to frame Min-Joon.

Min-Joon reveals his true self to Jae-Kyung before knocking him out. Song-Yi's brother notices her crush on Min-Joon, who keeps coldly rebuffing her.

Song-Yi finds Min-Joon in his apartment bleeding from a serious head wound. Lawyer Jang arrives and warns Song-Yi not to get attached to Min-Joon.

Song-Yi finally learns Min-Joon's secret. He also reveals that he'd wondered if Song-Yi is the reincarnation of Yi-Hwa, a girl he met 400 years ago.

Song-Yi is in the emergency room after an "accident" engineered by Jae-Kyung. Min-Joon plans to take the blame for all of Jae-Kyung's evil deeds.

Min-Joon confronts Jae-Kyung about all the lives he's been destroying. Song-Yi tells Min-Joon to stay away from her, but he does quite the opposite.

Min-Joon collapses after kissing Song-Yi. Hwi-Kyung awakes and pretends he knows nothing of Jae-Kyung's schemes. Min-Joon tells Song-Yi he must leave.

Song-Yi questions Min-Joon's need to return to his planet. MIn-Joon, like Song-Yi, is distraught at the prospect. Min-Joon's powers keep glitching.

Min-Joon says he won't leave after all, but Song-Yi doesn't know the real reason. Hwi-Kyung finally confronts his Jae-Kyung, rejecting him as family.

Song-Yi finds out about Min-Joon's likely death if he stays on Earth. Both Hwi-Kyung and Min-Joon attempt to force Jae-Kyung to turn himself in.

Song-Yi insists that Min-Joon should return to his planet. Min-Joon has dinner with Song-Yi's family, and her mom learns he's an alien.

Min-Joon professes his love for Song-Yi and then vanishes. Over time, Song-Yi and others think they catch a glimpse of him, but are they imagining it?