Three childhood friends went to a fireworks festival. On the way back, they were caught in a sudden downpour, and one of them got separated, leaving Natsu alone. Natsu was a little childish, and a childhood friend I'd been close with, like a little sister, but recently she'd suddenly become more girly, and I'd started to feel strangely self-conscious about her. Her yukata was soaked in the rain, revealing a thin layer of her underwear. She suddenly looked sexy, and her expression was different from usual, and my heart started beating wildly. As the rain got heavier, the two of us ran into a love hotel. We were never meant to cross the line, but this heavy rain drove us crazy one night.