Title: 블루버스데이 / Blue Birthday
Genre: Romance, Fantasy, Mystery
Episodes: 16
Broadcast network: Naver TV
Broadcast period: 2021-Jul-23 to 2021-Sep-11
Air time: Friday & Saturday

Oh Ha Rin (Yeri) is a 28-year-old woman whose heart still yearns for her first love and closest friend Ji Seo Jun (Hongseok). They were once as close as could be, and both had strong romantic feelings for one another. And exactly a decade ago, on the fateful day when she turned 18, she had resolved to finally come clean about her the way she felt about him…only to discover that he had taken his own life. She later discovered a note where he too confessed his romantic feelings for her.

Now, 10 years on, she looks back at the tragic day. And while looking through his belongings, she happens upon a pile of eight imperviously unseen photos Ji Seo Jun had kept hidden away. Distraught by the painful memories, Oh Ha Rin burns one of the photos – only to find herself back in high school at the exact moment at which the photo was taken. Realizing that she has been gifted the power to travel back in time, she resolves to find a way to save Ji Seo Jun. But she must be prudent: With every photo she burns, she loses another chance to save his life!