Traffic police officer Beom-su encounters college student Hyun-joo after she has a minor car accident. Taking an unconventional approach, he gives her driving lessons on a playground. Their shared dreams—him of becoming a baseball umpire and her of acting—deepen their bond, resulting in an exchange of 47 letters. However, their budding relationship is interrupted when Hyun-joo decides to study acting abroad.

Years later, Beom-su has become a renowned baseball umpire, while Hyun-joo is now a successful actress. Their worlds collide again at the opening ceremony of the Korean Series. As the star guest and the officiating umpire, their secret meetings reignite old feelings. But their reunion is complicated by rumors, a persistent reporter, and the advances of a smitten ramen company CEO.