My beloved daughter Ichika got married. I was so sad to see her leave that I remodeled our house into a two-family home, even though I was called a doting parent. My wife Momoko was happy to be living with our daughter and son-in-law, Hajime, and our relationship was also good. We had a happy family life with no complaints at all. Until that day... At some point, Momoko started to find various excuses to visit our daughter and son-in-law's house more often. Not only that, but she also started going out with our daughter...