Just after moving to a new apartment complex, Jung-tae meets his sexy next door neighbor, Yoomi. To his shock, he discovers she is an alien with an insatiable thirst for semen, and the two begin to enjoy secret sexual encounters. Complications soon arise when Yoomi’s husband comes back from his business trip, but while Jung-tae knows it’s wrong, he just can’t get the sexy alien next door out of his mind!