Ki Moo-Hyeok is a lawyer with a high winning rate. He only cares about money. Due to a murder case at a high school which he deals with, his reputation as a lawyer hits rock bottom. In order to regain his good name as a lawyer, he sneaks into the high school and begins to work as a temporary teacher. He tries to reveal a secret which the students have. In so doing, Ki Moo-Hyeok gets involved with Teacher Ha So-Hyun. She is P.E. teacher who loves her students. Ki Moo-Hyeok and Ha So-Hyun then face the students’ secret.