A romantic film about a man struggling with a painful past as he tries to move forward, only to discover that the woman in his present life has an uncanny connection to his past. Together, they navigate the complexities of love, heartbreak, and healing, all against the backdrop of cultural and identity differences in the foreign city.
33-year old Han Je In is a mystery novelist who is notorious for habitual false reporting to the police in town. Her only friend is police officer Rok Hwan, who has had a crush on her since childhood. One day, Je In hears a scream of help from an apartment upstairs and reports that a serial killer lives above her but no one believes her. Convinced that Jason, the handsome man living upstairs, is a serial killer, she asks Rok Hwan to help follow him around with her. But as she learns more about Jason in her pursuit to uncover the truth, she begins to fall for him. Seeing her in this state, Rok Hwan feels a tinge of jealousy.
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.
Matsumura Ryouko is a popular novelist in her 50s who has just found out that she has Alzheimer’s disease. In order to gain some fulfilment in her life, she decides to be a guest lecturer at a university. Through one of her students, she meets a South Korean exchange student, So Chan Hae. As they become closer, they fall in love.
Mika goes all the way to Seoul to see her sweetheart Hyeong Jun who's been waiting for her. She suffers faints at the airport and she mistakes Kim Gyeon as Hyeong Jun due to trauma. Kim Gyeon also ends up falling in love with her, thus disrupting the balance between the three. Their memories start intertwining, but, before long, a tragedy occurs.
Hitomi, a Japanese resident, comes to Hong Kong after the death of her fiancé Tatsuya in a fatal accident to settle several important matters surrounding his demise. Although the incident was years ago, it has apparently left an indelible mark in her life as she could not forget him. Kar Bo, an undercover cop, was involved in a drug bust-up which would later incriminate him. Hitomi stumbles into him and was amazed that he looked remarkably similar to her dead lover. Although Hitomi was conscious that Kar Bo can never be the real Tatsuya, she endures his hardships with him unfailingly which results to having strong feelings for each other.
Aoi studies photography at a school in Tokyo. She undergoes a heart transplant operation and goes to the island of Okinawa to recover. Her uncle lives on the island. There, she holds a camera and walks along the island. Aoi hears the sound of a trumpet. She looks up and sees a young man playing the trumpet. His name is Ji Oh.
Emilia, a Filipino who arrived in Japan with aspirations of becoming a model, coincidentally encounters Matsuyama Mirai, an aspiring photographer. Their connection deepens as they find themselves drawn to each other. Mirai, intent on immortalising their moments together, diligently captures their essence through the lens of his camera. However, an unexpected parting disrupts the flow of their narrative. Subsequently, the saga of these two individuals unfolds beyond the shores of Japan, traversing the vast sea to the Philippines, where their story takes on new dimensions.