Ram, a CIA agent, is assigned to infiltrate a mafia group in Thailand, even though he is reluctant due to the grief of losing his brother Luks, whom he believes his stepmother is responsible for. Meanwhile, Mae, a stubborn orphan and new flight attendant, accidentally ends up with an important pen linked to Ram’s mission after it gets switched during a flight to Korea. As Ram follows Mae and her friend to get the pen back, their constant arguments gradually turn into attraction and eventually love, despite misunderstandings and complicated situations.