Who's in the cast:
Yoo Ji-tae as Han Jae-hyeon
Park Jin-young (Jinyoung) as young Jae-hyeon
Lee Bo-young as Yoon Ji-soo
Jeon So-nee as young Ji-soo
When My Love Blooms follows the story of two old flames that had history during their college days but haven't seen each other in over a decade.
Present-day Han Jae-hyun gets released from prison after four years. He took the fall for his father in law, the Chairman of Hyung Sung over stock manipulation and embezzlement. He was promised the title Vice Chairman once he returns but maintains his director title instead. His wife, Seo Kyung was promoted to CEO of the company instead and they have a son together. They live a lavish lifestyle with a mansion, fancy cars with drivers, and expensive designer clothes. Unfortunately, Seo Kyung has been cheating on Jae-hyun since his time in prison.
Yoon Ji-soo is a divorced mother with a love for the piano. She spends a lot of her time attending protests and keeping her friends company. She lives a humble life in a small home while her 14-year-old son, Young-min goes to a prestigious international boarding school on an academic scholarship. She's forced to attend extravagant social gatherings with wealthy school moms while pretending to fit in. Ji-soo realizes that her protesting days will have to come to an end soon because her sick father's nurse is requesting for more pay. She feels sorry for her fellow protesters and tries to attend at least once a week for now.
Back in April 1993, Yoon Ji-soo was a college student. There were massive protests by students going up against armed military. The protesters wearing masks would swing sticks to defend themselves. The police had shields and would shoot their guns into the air. Student protesters would be beaten with batons for fighting back and for throwing Molotov Cocktails (firebomb) which filled the air with smoke.
Ji-soo wasn't involved but would have to journey across the battlefield just to get to class. She happened to be walking when a large smokescreen made it hard to see or breathe. Everyone started running to escape and she gets knocked down. As she sits there unable to see or breathe, someone grabs her hand and pulls her to a safe area. He tells her to take deep breaths and wraps her injured hand with the handkerchief he was using as a mask. After helping her, he runs off before she could ask for his name.
After that incident, she couldn't help but search for her hero. She goes around trying to find out when the next protest will take place and even mistaken a few different people for him. Ji-soo eventually figures out her hero's name when he introduces himself as Law Student Han Jae-hyeon of the freshman class '91 during a speech. He was speaking about his desire for the liberation of labor and liberal democracy during the remembrance of the 13th anniversary of the May 18 Gwangju Democratization Movement.
Ji-soo gets drawn to Jae-hyeon and starts to follow him around secretly. She goes to his club room but when he sees her standing there, he closes the door in her face. She debates on throwing his handkerchief away instead of trying to return it to him.
In May 1993, Ji-soo goes to borrow the movie Love Letter. She runs into Jae-hyeon who reserved the movie first, but he ends up leaving and letting her take it. She chases after him asking him to watch it together and insisted that no one would believe her that an activist senior wanted to watch a melodramatic Japanese movie. He asks her if she understands Korean as he rejects her offer again.
Persistent Ji-soo wanders around campus looking for Jae-hyeon to repeatedly ask him to watch the movie together while holding the tape. Eventually, he gave in. Ji-soo had a habit of exercising her fingers to which Jae-hyeon told her it bothered him. After the movie, she tells him she usually practices the piano alone in the music building on Wednesdays and asks when they'll get to see each other again. He confusingly asks why they would need to meet again. She boldly smiles and responds because they'll miss each other.
Ji-soo tells him that she also wants to protest and mentions she used to be a horseback rider when she was young. Jae-hyeon tells her that he protests against rich families like hers so how would they react knowing their pampered daughter hangs around a protester. Her bus arrives and Jae-hyeon pushes her to go against her will. As the bus leaves, she shouts out the window, "I won't give up! So you should give up! I will date you, even if it's the last thing I do!" He looked around embarrassed but a smile escapes.
Current day Jae-hyeon can't help but reminisce about Ji-soo and wondering how she's doing. He'll watch the movie Love Letter or read a book she gifted him in the past. He's been trying to locate her for a long time, but can't find her no matter how hard he searches. She was forced to go into hiding at some point. His friend comforts him that Ji-soo might look fragile and delicate but she was a total warrior in college.
Young-min has been getting bullied at his school. The other students are aware that he's not from a wealthy family and is attending on an academic scholarship. One student, in particular, makes his life a living hell. One day, Young Min snaps and throws a chair at the other student. Ji-soo receives a call from the school and rushes there by train and taxi. She thinks back on the day she divorced her ex-husband, Lee Se-hoon. She rejected all monetary compensation including alimony and child support in return for just custody. She didn't want to raise her son with money from Se-hoon or his mother. He threatened to sue her for custody if anything ever happens to Young-min and he won't give up on her either as long as they have a son together.
Jae-hyeon receives a call from his wife that their son, Joon-seo had gotten injured. He drives to his son's school to find him sitting in the nurse's office. He asks his son what happened and if he's okay. His son claims that this poor kid suddenly went psycho and threw a chair at him for no reason. Jae-hyeon questions his son because a similar incident happened in the past. Joon-seo denies doing anything wrong and says the other boy is a lame, loser bastard.
While Jae-hyeon was sitting in the school office, Young-min's mother enters the room. She doesn't look up at anyone but sincerely apologizes. Jae-hyeon recognizes her voice and notices she was doing finger exercises as she spoke. He looks up at her and walks out of the room before she got a chance to see him. He tells the school that it wasn't a big issue so they don't need to open a school violence case.
Ji-soo tries to talk to Young-min, but he refuses to tell her anything. She ends up walking to the train station late at night in the snow. Jae-hyeon purposely leaves his car to walk behind her. He notices that she's saved his handkerchief all these years. He stands outside the station waiting for her to come back out knowing that they've missed the last train. He walks over and stands next to her. He tells her not to worry about the school incident as she stands there shocked to see him. They can't help but both tear up as they stare into each other's eyes again.