When Jo Gang-Ja attended high school, she was notorious for fighting. She gave birth to her daughter A-Ran in her late teens and became more responsible. Her daughter A-Ran is now a high school student, but A-Ran is bullied at school. Jo Gang-Ja decides to go back to high school to protect her daughter. Jo Gang-Ja becomes a high school student again.

• Kim Hee-seon
• Ji Hyun-woo
• Kim You-jung
• Lim Hyung-jun
• Koh Soo-hee
• Kim Seul-ki
• Jeon Kuk-hwan
• Kang Moon-Young