娘の一花が結婚したタイミングで、親バカの私は二世帯住宅にリフォームをしました。同居は円満で娘婿の慎二君ともいい関係を気づけていたのですが、あの日を境に全てが一変しました。妻・冬香が何かにつけ、娘夫婦の家に行く事が増え始め、娘と有り得ない約束をしたと思ったら、娘はそんな約束をしてないという不自然な嘘をつき始めて…。

When my daughter Ichika got married, I, being a doting parent, renovated our house into a two-family home. Living together was harmonious, and I had a good relationship with my son-in-law, Shinji, but everything changed after that day. My wife, Fuyuka, started visiting our daughter and son-in-law's house more and more often, and then, after making an unbelievable promise with our daughter, she started telling unnatural lies, claiming she never made such a promise…