Beautiful Summer Nights Somehow End in Disaster

Kagura and Okita are kidnapped by the Harusame, and Kagura's older brother isn't responsible? Who is responsible for kidnapping them and why? How do Kagura and Okita plan to get back home to Earth? How does Kagura plan to handle a Sadist that is constantly sexually harassing her? Why is this summary full of nothing but questions? Want to read and find the answers?