Watch Blue BirthdayTV-142021|1 season|Sci-Fi & Fantasy,Drama,MysteryPlay TrailerAdd to WatchlistHer first love passed away on her birthdayStoryThe series tells the story of Oh Ha-rin, who travels to the past through mysterious photos left by her first love, Ji Seo-jun. Since they were eight years old, they had been close friends, but he died by suicide on her birthday ten years ago.