My beloved daughter Ichika got married, and despite being called doting parents, we renovated our home into a two-family residence. My wife Momoko was delighted to live under the same roof as our daughter's couple, and she built a good relationship with her son-in-law Hajime. We continued living happily without any complaints—until one day, Momoko started visiting her daughter's side of the house unusually often. I began sensing something off as Momoko displayed strange behaviors, like claiming our daughter had gone out when she was actually still at home, and her lies gradually multiplied.