Professor Kim Jin-woo
Vital statistics
Status Alive
Gender Male
Age 50+
Occupation Mathematics Professor
Health Alive
Other Info
Cast in Drama Jung Dong Hwan
Anime Vocal Bae Han Seon


Prof. Kim Jin-woo, as the name suggests, is a mathematics professor. He is the most trusted friend and confidant of Jung Hyunsoo. He used to conduct private math classes for Joonsang. He is the person who sheds light on the question of Joonsang's true father. He is Joonsang's father. He is married to Kim Jung.


He possess a kind and intellectual face ,thereby he is well-respected among other individuals as a professor in a university. Being a University Professor, he often wears a semi-formal suit for his classroom discussions. He wears glasses and usually dresses up in formal suits for most occasions.


He is a calm and reserved person, who takes his teaching profession seriously. Providing additional support and help to interested students like Joonsang.

He can also be very persistent about certain things like the question of Joonsang's true father.


Jung HyunsooEdit

He is the most trusted friend and confidant of Hyunsoo. He was entrusted with the musical composition First Time which Kang Mee-hi played in their wedding with Kim Yeonhee.

Kang Mee-hiEdit

Prof. Kim was always in love with Kang Mee-hi. But she would only accept Jung Hyunsoo as her lover. He fathers Joonsang with her.

Kang Joon-Sang/Lee Min-HyeongEdit

Joonsang was Prof. Kim's star pupil. He had left such a good impression that the Professor never forgot him. Prof. Kim is Joonsang's true father which is revealed by a DNA test.

Kim JungEdit

He is married to Kim Jung and has a son with her. At first part of the anime series, they make a well-going couple but when he discovered that he had a son name Joonsang from Kang Mee-hi, it made her to be ill and show apathy toward his husband.

Kim SanghyeokEdit

He is more than a just father to Sanghyeok, acting as a friend and helping through all his emotional turmoil.

Kim YeonheeEdit

She is close family friend of Kim Jinwoo. They were always on good terms with each other thanks to his friendship with Jung Hyunsoo.

Jeong Yoo-jinEdit

Prof.Kim is like a father to Yoojin and is always by her side.


At the start of the anime series, he always appeared in a classroom or faculty lounge interacting with students. He was often seen discussing things with Joonsang regarding mathematics. But Joonsang would often ask him about Kang Mee-hi ,and things which would throw light on his fathers's identity.

He was always doubtful as to who Joonsang's father was. Never completely convinced of Kang Mee-hi's word, he asks a doctor to do a DNA profiling on Joonsang in the sequel. The test proves that he is Joonsang's father and not Jung Hyunsoo.


  • He is an excellent Mathematics teacher.


  • He is able to recognize the best student Joonsang even after a gap of ten years.