故事讲述安乐冈花火（吉本实忧）和粟屋麦（樱田通）表面上一对理想的高中生情侣，内里却是各自喜欢别人。花火喜欢钟井鸣海（水田航生），二人是青梅竹马，他对花火来说就像哥哥，现在是花火的班主任。粟屋喜欢的是校内的音乐老师皆川茜（逢泽莉娜），然而鸣海却喜欢她。花火和粟屋因为同病相怜，产生了和对方相近的感觉，于是成为「契约恋人」，互相安慰取暖。池上纱理依演花火的好友绘鸠早苗，1月18日首播！动画版1月12日，实现日剧动画同步播放的计划。

De zeventienjarige Mugi Awaya en Hanabi Yasuraoka lijken het ideale koppel. Ze zijn allebei behoorlijk populair en lijken goed bij elkaar te passen. Buitenstaanders kennen echter niet het geheim dat zij delen. Zowel Mugi als Hanabi zijn hopeloos verliefd op iemand anders, en ze gaan alleen met elkaar uit om hun eenzaamheid te verzachten. Mugi is verliefd op Akane Minagawa, een jonge leraar die vroeger zijn huisleraar was. Hanabi is ook verliefd op een leraar, een jongeman die al sinds haar kindertijd een familievriend is. In elkaar vinden ze een plek waar ze kunnen rouwen om degenen die ze niet kunnen hebben, en delen ze fysieke intimiteit, gedreven door eenzaamheid. Zullen de dingen voor altijd zo blijven voor hen?

Seventeen-year-old Mugi Awaya and Hanabi Yasuraoka appear to be the ideal couple. They are both pretty popular, and they seem to suit each other well. However, outsiders don't know of the secret they share. Both Mugi and Hanabi have hopeless crushes on someone else, and they are only dating each other to soothe their loneliness. Mugi is in love with Akane Minagawa, a young teacher who used to be his home tutor. Hanabi is also in love with a teacher, a young man who has been a family friend since she was little. In each other, they find a place where they can grieve for the ones they cannot have, and they share physical intimacy driven by loneliness. Will things stay like this for them forever?

月刊「ビッグガンガン」（スクウェア・エニックス刊）にて連載中の、横槍メンゴ作の漫画「クズの本懐」を原作としたドラマ。

主人公、高校2年生の安楽岡花火（やすらおかはなび）と粟屋麦（あわやむぎ）が、実は誰にも言えない秘密の契約を結んでおり、不条理な感情を慰め合い堕ちていく。今回ドラマ化の他にも、アニメ版『クズの本懐』が、2017年1月12日（木）よりフジテレビ木曜深夜放送のアニメ枠「ノイタミナ」にて放送が決定しており、同一原作の作品をドラマ、アニメと同時に提供する新しい試み。

이제 17살인 아와야 무기와 야스라오카 하나비는 이상적인 커플로 보인다. 둘 모두 학교에서 유명하고 서로 잘 어울리지만, 다른 사람들은 모르는 두 사람만의 비밀이 있다. 무기와 하나비 모두 다른 사람을 짝사랑하고 있고 외로움을 달래기 위해 만나고 있을 뿐이다. 무기는 어린 시절 과외 선생님이었던 학교 선생님인 미나가와 아카네를 사랑하고 있고, 하나비는 어릴때부터 가족처럼 지낸 이웃오빠였던 학교 선생님을 좋아하고 있다. 서로, 가질 수 없는 것에 대한 슬픔을 토로할 수 있는 상대가 되면서 외로움에 대한 반발로 육체적인 친밀감을 공유하게 된다. 이런 관계가 계속될 수 있을까?

Yasuraoka Hanabi e Awaya Mugi aparentam ser o casal ideal. Eles são bastante populares e parecem combinar um com o outro. No entanto, o que os colegas não sabem é que eles compartilham um segredo. Ambos estão interessados em outras pessoas, pessoas essas 'impossíveis' para eles. Hanabi gosta de Kanai Narumi desde quando ela era criança e Mugi nutre sentimentos pela sua professora particular Minagawa Akane. Os dois então firmam um acordo de namoro para aliviar as suas dores e solidão. Mas será que as coisas ficarão assim para sempre? Ou algo irá mudar seus sentimentos?