My cousin Ayu san is one year older than me and has a bright personality. I hadn't had a phone call in a while... but she suddenly said she was staying at my house for a while! She barged into the bath saying, "We used to take baths together!" It was too much stimulation for a virgin like me... I was masturbating to her naked body and she found me and we had sex and lost my virginity! I never knew Ayu san had become so erotic... My life under the same roof with Ayu-san has begun!