Singer Hyeon Seok develops problems with his hearing (Menieres syndrome) and has to stop his recordings. He notices a picture of Hokkaido in a magazine and decides to travel there. He eventually arrives in a a small village in Hokkaido for rest. While there, he reminisces about the old days. The owner of the inn offers him a Japanese meal. There he meets a bright cheerful girl named Megumi.
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.
Joe Yabuki is an aimless young man who runs away from an orphanage with no money and no place to stay. He runs into a former boxing trainer, Danpei, who still has a strong passion for boxing. Danpei watches Joe fight and regains his desire to train future boxers. Joe, however, does not have any interest in boxing until he ends up in a juvenile prison where he meets Rikiishi, a former boxing prodigy. They quickly develop a rivalry, and a newfound interest in boxing overcomes everybody in prison, including Joe.
Woo Hyun is a Korean man, and Haruka is a Japanese woman. They live different lives, but they both carry emotional scars from their first love. While looking for answers and hope, their fateful encounter will change their lives. It started with one message… Haruka, a stage actress in Seoul, has been in a slump ever since she broke up with her first love. She cannot forget him and keeps sending messages that go unread on LINE. Despite her emotional hurt, Haruka wants to believe in love. In Tokyo, Woo Hyun, an aspiring movie director, keeps on doing interviews concerning “love”. After being deeply hurt by his girlfriend, who thought about getting married, he no longer believes in love. Haruka and Woo Hyun have both grown timid of love. The two of them, who live apart in Tokyo and Seoul, have a chance encounter because of a LINE message delivered to Woo Hyun’s smartphone from Haruka. They exchange messages without knowing each other’s faces and are drawn to each other before they realise it
Hatanaka Kosaku is a talented boxer who turned pro at the age of 19, winning his debut match with a first-round KO. He is talented, but he has no guts. His uncontrollable appetite is an even bigger problem. He can't put himself in the right weight class, he runs out of energy because of hunger, and he gets knocked out while his eyes are set on food at the ringside. However, Kosaku's life changed when he met Sister Angela, a novice nun in the convent near his boxing gym. She became the source of his power, and Kosaku fights only to win her heart.
