Five years into our marriage, we still don't have children. We live in a second-hand condominium we bought with a mortgage. Over time, the interior began deteriorating, so after discussing it, my wife and I decided to renovate—what people call a "renovation." Starting every morning at eight, a carpenter in charge of the interior work began coming to our home. He looked tough and silent, a weathered middle-aged man with a rugged charm. My wife and I exchanged awkward smiles, politely and carefully watching over his work, saying "Please take care of it." But gradually, within this ordinary routine, both our home and our relationship as a couple began to change...