It's been six years since I started living with my girlfriend. As we've been living together, it's undeniable that our nighttime activities have become less frequent. Then, one day, I hear her sister is coming to stay from the countryside. When I get home from work, I'm shocked! My eyes catch a glimpse of her braless, defenseless body, peeking out from under her shirt. I'm captivated by the unbalanced, erotic gap between her baby-faced, small-animal-like idol face and her H-cup breasts...