Who is Isobe from Deep River and what is their importance?

During Isobe's younger life, he is a quite man who concentrates on work. He has a wife and an adopted daughter, but he expects his family to silently serve him, and he does not show them outward signs of affection. This drives his adopted daughter away, but his wife seems happy to quietly care for her husband. Isobe has more than one affair, and he does not think of his wife as a woman, a sexual being. Instead, he thinks of marriage as a partnership of convenience in life.