Aya lost her husband in a random murder case. Since then, she raises her son alone and also runs a curry restaurant. She feels she can't be happy again. At that time, Aya meets Ryoji. Ryoji used to be a promising lawyer, but he got involved in the random murder case. He fought against the murderer and killed Aya's husband by accident. Due to the traumatic incident, Ryoji is unable to speak and now drives a truck for a living. Aya and Roji know they can't be together, but they fall deeply in love.

コントレールとは英語で「ひこうき雲」のこと。そしてヒロインにとってはすぐに消えてしまう幸せの象徴。無差別殺人事件で夫を失った孤独な女が絶望の淵で出会った恋の相手は、夫を殺した男だった。 愛してはいけない相手と知ってなお、激しく求めあう二人。そんな女を想い、その恋をそっと見守る心優しき刑事。 人生には、どんなに苦しい時でも、思いがけない出会いが訪れる。「セカンドバージン」「ガラスの家」を超えた、切なく激しい大人のためのラブストーリー。

6년 전에 살인사건으로 인해 남편을 잃고, 5살 아들을 홀로 키우고 있는 여자와 트럭 운전기사로 일하고 있는 남자가 사랑에 빠지게 되면서 일어나는 이야기를 그린 드라마