Yui Shiota, a freshman at university, lived her daily life as time went by. One day, She suddenly pick up the "Utsurundesu" She bought on my way home. She remembered her friend Shizuku Ichinose when she was in high school and a promise she couldn't keep. The current self and the self at that time. Relationship with best friend. A blue story that delicately weaves memories and emotions.