After finishing summer lessons and returning home, I found a beautiful woman standing on the veranda. As I approached, I realized it was my older sister—seven years my senior—whom I hadn't seen in five years. Surprised to see her, I was struck by how stunning she had become, yet I struggled to find words, feeling awkward and flustered. As we casually ate watermelon together, our conversation flowed naturally, just like in the old days, as if time had turned back. But the sight of her smooth skin visible through her yukata, her cleavage, and the delicate curve of her neck gave off a subtly seductive aura. Then, when she suddenly touched my cheek, I instantly became aware of her as a woman. Whether she sensed my reaction or not, she gradually began exuding pheromones, pushing my restraint to the breaking point. Before the others come back, before the private tutor arrives—I can't let this moment slip away.