Love comes in all flavors. Secret Ingredient is the story of a Korean man who gives up his entire luxurious life in Seoul in search of his childhood girlfriend, someone he’s never forgotten all these years, in the hopes that she would fall in love with him, not for who they were back then or who they are now, but for what they can aspire to be: happy, fulfilled and blissfully in love with one another.
On a spring day Munakata Ikujou visited an old temple to view a 1000 years old sakura tree. There Ikujou discovered a 3-year-old girl and adopted her as his own daughter. 16 years later, Sakurako has grown up to become a beautiful woman. Sakurako then has a fateful meeting with Takanashi Hiroto. Their pure love begin.
When his boss, Dae Jung, goes missing in a ship accident, the company sends Woo Joo to Osaka to finish his business. On his last day in the city, Woo Joo chases someone looking exactly like Dae Jung to Taisho, an area in Osaka. He ends up losing him, but the sound of a guitar draws Woo Joo to a small bar, Pier 34. Its owner, Snow, somehow reminds him of Dae Jung, and listening to his music brings back memories. After passing out right there, Woo Joo ends up missing his flight back to Korea. He quits his job on a whim and soon meets Haruna, who is learning how to play the guitar from Snow. Woo Joo decides to stay at Pier 34 until he finds Dae Jung and so begins an unlikely vacation for him.