Da Yeon is the chairman's youngest daughter, and she is one of the three most influential people in the Happiness class along with Baek Ha rin and Seo Do ah. She is rude, harsh, cold, short-tempered, frightening, cruel, impatient, dominant, nervous. She is extraverted sensing thinking perceiving girl. Kim Da Yeon has daddy issues, her dad is a weak spot for her, as her father beats her. At school, she relieves stress by bullying her classmates. Her height is 172 centimeters. She is pretty girl.