No Longer Human (No Longer Human #3)

Yozo lulls into a sense of comfort with his new life and wife, but his life shatters when he discovers the love of his life is worse off than he. After a business acquaintence sexually assualtes his wife, Yozo stops invisioning her as the woman who tamed his soul months before. Now, his wife charms men. Instead of confronting her or threating divorse, Yozo moves on, but moving forward towards nothingness advances nothing. People see it as the end. From here on out, Yozo's life turns subhuman.