Six months ago, my brother got married and his wife came to live with us. My brother's wife is one year older than me and is very sexy, friendly and cheerful. But there's one problem... My sister-in-law's sexy underwear is on the laundry. I'm not familiar with sexy underwear, so it's exciting for me, and it reminds me of my sister-in-law... One day, I found out a secret about my sister-in-law that even my brother didn't know about.