While Nishimura Kanade was a 3rd grade middle school student, her father, who worked as a prosecutor, died in an incident. After her father's death, she and her mother moved to her mother's hometown in Nagano Prefecture. Nishimura Kanade wanted to become a prosecutor like her father, and she entered law school at a national university in Nagano Prefecture. There, she had 4 friends, including Nogi Masaki. They became really close friends and shared memorable experiences together. Due to a case involving a death, their relationship ended. 

12 years later, Nishimura Kanade is now 35 years old and works as a prosecutor in the Yokohama District Public Prosecutors' Office. Her boyfriend is Okuda Takashi, who works as a doctor, and they live together. One day, one of her law school classmates, who disappeared after the death case, appears in front of her. Nishimura Kanade must confront the suspicious death case from her law school days. This leads her to examine the truth behind her father's death from 20 years ago and also the secret faces of her friends.