After living in December 24th, Christmas Eve on endless repeat- Mokhwa seems to be the only one who's aware of the existence of the time loop. And on this repeated day, he spends time with his childhood friend 'Choi Gyun' despite having cut ties with him a long time ago.
Having to work a part time job in a Bom-Mart, Hajun gets harassed by his manager Wookyung without a reason. One day, he was ordered by Wookyung to arrange the cold storage and gets trapped with Wookyung, who came to check on him. But thinking that they'll die in the cold storage, Wookyung suddenly starts to confess to Hajun that he harassed him because he liked him?!
On his first day working as a new teacher at his alma mater, Sunny Day Boys High School, Lee Taesung is welcomed by the bright and sunny smile of Seo Sunny, a warmhearted chemistry teacher. Feeling immediately drawn to Sunny, who resembles his first love from high school, Taesung tries to hold back his feelings by keeping his distance. But still, Taesung can’t help but be pulled in by Sunny’s irresistible charm…
Introduction to the Theory of Love