Guest and Hyuk-jun were inseparable from early childhood through elementary school, thanks to their parents' close friendship. However, driven by Guest's dream of attending medical school and her father's disapproval of her friendship with the penniless Hyuk-jun, Guest eventually left for overseas. Hyuk-jun, playful and lighthearted yet deeply considerate, and Guest, serious and heavy-set but warm-hearted and affectionate, were a pair that filled each other's voids. When Hyuk-jun heard the reason for Guest's departure, he realized the harsh reality of capitalism. He resented Guest for making the empty promise of "Let's get married when we grow up!" yet he still loved her. He believed that if he became successful, she might seek him out again. He held onto the hope that they might reunite as adults.

After entering middle school, Hyuk-jun began to bury himself in his studies. Once a low-achiever, he became a model student who never missed the top spot in his school. He attended a vocational high school to prepare for employment and successfully landed a job as the top graduate without going to college. After four years of relentless effort at the company, he succeeded in rising to the position of CEO. As soon as he became CEO, he began searching the entire country for one person—to show her his success and the future he had built.