"The story begins a few years after high school graduation, when the main character Mizuho receives an unexpected phone call. She learns of the passing of a high school classmate named Haruka Origuchi. Haruka was a plain girl who did not draw attention, but Mizuho discovers to her shock that Haruka was pregnant during high school. Now, Haruka's mother wants Mizuho's help in finding the father of Haruka's unborn child.
Even as she assembles the puzzles pieces of Haruka's life, Mizuho fears delving too far in her past. Mizuho shared her first kiss with a boy named Hikaru Narumi in high school, and their lives may cross paths again." (ANN Drama Announcement)