When my daughter started kindergarten, my wife started working part-time at a supermarket along the national highway. She seemed to be enjoying it, and it helped our household finances, so I watched her with a smile as her husband. However, recently, a young man named Kei, a university student who said he was working part-time at the same supermarket as my wife, started coming into our house frequently during the day and drinking tea and chatting with my wife...!