Top-ratedS1.E1 ∙ Episode #1.1Sun, Jan 7, 2018A math teacher went back 10 years to his high school life where he met all his friends and family including the girl he could never confess. As he met his younger self too, he took it as a challenge to fix the past.8.8/10 (6)Rate
S1.E2 ∙ Episode #1.2Mon, Jan 8, 2018As the sports festival approaches, Shin Woo does everything in his power to force his younger self into Na Hee's life.Rate
S1.E3 ∙ Episode #1.3Sun, Jan 14, 2018The younger Shin Woo is prodded into confessing to Na Hee. But who does Na Hee truly like?Rate
S1.E4 ∙ Episode #1.4Mon, Jan 15, 2018The older Shin Woo and Ji Soo spend an awkward night locked in the school. Will Shin Woo give in to his desires?Rate
S1.E5 ∙ Episode #1.5Sun, Jan 21, 2018With all of his business wrapped up, the older Shin Woo decides it's time to head back to the future, but the only problem is how to do it.Rate
S1.E7 ∙ Episode #1.7Sun, Jan 28, 2018With the younger Shin Woo in the present day, the race to win Ji Soo's heart intensifies.Rate
S1.E8 ∙ Episode #1.8Mon, Jan 29, 2018Ji Soo drunkenly mistakes Shin Woo for her teacher. Will he tell her the truth?Rate
S1.E9 ∙ Episode #1.9Sun, Feb 4, 2018After learning the truth about Ji Soo's odd behavior, Shin Woo turns over a new leaf.Rate