Since she was little, Karen dreamed of becoming a teacher. She tried her best and finally made her dream come true. After a week of internship at the new school, she was assigned to be the homeroom teacher of a class. She tried her best to memorize the students' names and called them by their nicknames. Karen was very popular with the students and they all loved her except Hayato. He often skipped school and fought with students from other schools. Karen wanted to help him and wanted him to open up to her. She often met and talked with Hayato, and wrote a diary with him. Gradually, feelings formed between the two. Although she knew that this was not allowed and could ruin Karen's childhood dream, she loved Hayato! They ran away together to go on a date, went to the hot springs together, and enjoyed the moments of a couple. I love you. After I graduate, let's get married. A beautiful but forbidden love, the two were separated but their hearts would be together forever.