A real-life treasure hunt for adults to find hidden 500 million won in cash!

Shota, a machinist who dedicated his life to his work, prepares for his final business trip to Korea before retiring. Meanwhile, Daesung heads to Japan to win back his ex-girlfriend. The two men happen to meet at a ramen shop on the first day of their journeys. When Shota's resignation letter and Daesung's love letter are swapped, an unexpected story begins.