|Age||around 28 years|
|Occupation||Musical Program Organizer|
|Cast in Drama||Park Yong-Ha|
|Anime Vocal||Kang Yo Hwan|
Kim Sanghyeok is the son of Prof. Kim Jinwoo who teaches math. He is Yoojin's childhood friend. Later it is revealed that he and Joonsang are half-brothers sharing the same father.
In his high school days, he had dark chestnut hair and a fair and kind looks. Along with time, his hair has grown darker.
Sanghyeok and Yoojin were childhood friends. He was attracted towards her even as a kid as he would say that they would get married when they grow up.His commitment to her continues from childhood to adulthood. They were also engaged till Yoojin finds out that Minhyeong is Joonsang.He would do anything for her even if it ment forsaking his love or life.
Joonsang is Sanghyeok's rival at school since they both rooted for the same girl ie Yoojin.Joonsang was also particularily hostile towards Sanghyeok adding towards the growing enmity between the two.
Professor Kim JInwooEdit
Prof. Kim is Sanghyeok's father and a math lecturer. The two are very close often behaving like friends.
Plot EditSanghyeok knows Yoojin from childhood since their fathers were best friends. He likes Yoojin but couldn't convey his feelings for her in high school because of Joonsang. After the accident, he stays beside her and 10 years later decides to marry her. They get engaged but the sudden appearance of Minhyeong turns the table. Yoojin finds out that Minhyeong is Joonsang and after he gets his memory back, they decide to get married. Sanghyeok suffers a lot of pain but being a good friend of Yoojin, he manages to accept everything. Later Sanghyeok's father tells him that Yoojin and Joonsang are actually siblings. So, it's up to him to stop their wedding. Unfortunately, he fails to do so. Then he meets up with Joonsang the next day as the latter decides to leave Yoojin. Later he learns that Joonsang is actually his half-brother not Yoojin's. But it's too late. After the break-up of those two, Sanghyeok starts dating Chelin. 3 years later, on the wedding day of Joonsang and Yoojin, he accompanies Yoojin.
- He manages a classical music radio station along with his father.
- He works as a musical program organizer.
- Upon resignation as musical program director, he eventually becomes a documentary director.