A touring program producer Min-joo, takes notes in her journal whenever and wherever she travels, so one day she can show all those amazing places to her longtime lover Hyun-woo. Finally Hyun-woo passes the bar exam and proposes to Min-joo. However, not long after, Min-joo dies when the department store where she was waiting for Hyun-woo collapses. Hyun-woo becomes a prosecutor, but when he digs too deeply in a sensitive political case, he ends up in detention. While in detention (five years after Min-joo's death), Min-joo's parents send him Min-joo's journal, which gives him a road to trace all the memories of his lost lover.