Hyung-min lives under one roof with his older brother Hyung-jin and his pregnant, exhausted sister-in-law Na-ri. Just as Na-ri is having a hard time, Teacher's Day arrives and Mi-seon, a former student, calls to check in. Hearing about her teacher's condition, she travels a long way to help with the housework. Hyung-min welcomes her warmly and shows her around. She is clumsy with cooking and chores and keeps making small mistakes, but her bright energy soon brings the house back to life. Doing all they can so Na-ri can rest, the three are moved by each other's warmth and confirm a deeper friendship and family bond.