After Jiwoo, who lives with his grandmother, suddenly disappears, police investigation begins, and statements follow from children who claim they were harmed by Jiwoo's problematic behavior. Then Gaeul, Jiwoo's only friend, makes a statement that Jiwoo is actually an alien who, unable to adapt to Earth, is returning to his own planet. Is Jiwoo really an alien from outer space who wants to return to his planet?