The Harmonium in My Memory(1999)

Original title: 내 마음의 풍금

Hong-yun is a high school girl in little mountain village when she falls head-over-heels for a handsome new school teacher, Mr. Kang. What with taking care of her youngest baby brother for her widowed mother and the impossible age difference, it is a roller-coaster ride for her as she tries to become someone special for Mr. Kang while he seems interested in the other new teacher at the school, Miss Yang.