Yongsoon (2017)

"That summer, I met my first love."

Yong-soon is an 18-year-old high school student. She falls in love with her gym teacher, but she thinks her teacher might have a girlfriend. Yong-Soon and her friends try to find out whether he does have a girlfriend, but they can't find any clues. Making things worse, her father brings a new stepmother from Mongolia.