In a suspicious car accident, Seo Jiwoon's sister dies while top actor Cha Taehyuk walks off unscathed. While trying to uncover the truth, Jiwoon is also hit by a car. However, when he opens his eyes, Jiwoon realizes he has traveled back in time to his first day of work. Will this opportunity to work together with Cha Taehyuk be the perfect opportunity to avenge his sister's death?