A woman goes back in time, through mysterious photos, to try to save her boyfriend's life.
EPISODE 1
My Bad Birthday
Ha Rin visits her old neighborhood and retrieves Seo Jun's old photos; since the photos remind her of the pain, she burns one of them.
EPISODE 2
You're in My Dream
When Ha Rin realizes that she had traveled back in time, she looks for Seo Jun; the dreamlike reunion only lasts for a short time and she is back to the present.
EPISODE 3
Lively Ordinary Days
Ha Rin decides to find out why Seo Jun had committed suicide 10 years ago; she checks what kind of books Seo Jun had rented, reaches out to his friends and also looks through his social media accounts.
EPISODE 4
Law of Equivalent Exchange
Ha Rin makes up her mind to prevent Seo Jun's death; she goes back to the past to resolve the conflict Seo Jun had with his mother.
EPISODE 5
Episode 5
EPISODE 6
What Happened That Day
Ha Rin manages to save Hye Min from her death; with Hye Min alive, Seo Jun is gone again; Ha Rin tracks down the clues to Seo Jun's death, and notices some weird things; she burns another photo to find out the truth.
Yeri
Hongseok
Lee Sang-jun
Kim Gyeol-yu
Park Ju-hyeon
Kim I-seo
Lee Dong-ju
Park Dan-hee
Kim Se-jeong
Moon Won-yeong
Goo So-yeon