I ended up staying at my aunt's house in Tokyo for a few days. I hadn't seen my aunt since I was a child, but her plump denim ass, which she herself was unaware of, gave off an erotic and elegant adult sexiness. Her big ripe ass made me horny, so I showed her how I masturbated. She had an innocent reaction, but I didn't miss the secret gleam in her eyes and continued masturbating in front of her. Then her sexual instinct gradually became exposed, and when I inserted my dick, she let out a roar and climaxed. She screamed like an animal, which you wouldn't imagine from her appearance. I was excited by her transformation, and one ejaculation wasn't enough for me, so I came inside her many times.