I live with my brother and his wife. I'm always soothed by Shiho-san's kind smile. One day, my older brother was on a business trip and it was just me and my sister-in-law Shiho at home. From there, the naughty relationship between the two began... He purposely came in while I was taking a bath, changed his clothes in front of me, and finally slept in the same bed... The forbidden relationship between big brother and brother continues today...