Ozaki Karin unexpectedly lost her childhood sweetheart and first love, Soma Jun, on her seventeenth birthday. On the day of her 27th birthday, ten years later, Karin just so happens to come across Jun's abandoned film camera and the pictures he had taken of her. She is prompted by this to recall all of her feelings for Jun. Karin burns all the pictures because she can't control her feelings, and as a result, she travels back in time to the day the picture was taken ten years earlier. Karin gradually learns the shocking truth about the passing of her childhood buddy as she switches back and forth between the past and present to prevent Jun's suicide.