In "Angry Mom" Kim Hee Sun plays Jo Gang Ja, a mom so angry about her daughter's treatment at school that she decides to enroll as a student to take on the bullies. In the drama she can still pass for a student because she became a mom when she was only a teenager. So, she is supposed to be between 32 and 35.

But while she is pretending to be a teenager, she acquires a protector. Another student, the teen played by actor Ji Soo, thinks that she is a teen and after admiring her tough girl ways develops a crush on her. There's plenty of chemistry between the two actors even though they are decades apart in age.

Kim Hee Sun, 38, is slender enough to look good in a school uniform and could pass for a slightly older student. But despite her youthful good looks, Ji Soo, last seen as a student in "To The Beautiful You," is still only 22.

Korean media outlet Naver TV asked the actress about the chemistry between them and the question caused her to laugh.

"I'm sorry," she said. "We have more chemistry than I would have imagined."

The actress, who is married to Korean businessman Park Joo Young, said she is living vicariously through the drama.

"I had no idea he'd be so kind to me," she said of Ji Soo's character.

Ji Soo plays Go Bok Dong, a student who is forced into a life of thuggish behavior because he feels he has no other choice. His feelings for Jo Gang Ja, who he believes to be a high school troublemaker like himself, cause him to question the choices he has made so far.

What will happen when he finds out that she is not really a student, but a mom out to uncover the dark secrets hidden by the school's power brokers? Viewers will have to wait until the next episode to find out.

"I'm curious to see what happens when my character's identity is revealed soon," said Kim Hee Sun.

Kim Hee Sun previously played love scenes with another younger co-star, Lee Min Ho, in the historical drama "Faith: The Great Doctor." Lee Min Ho is 11 years younger than Kim.

The next episode airs on April 22.