Naoto Kiyoshi is a young man who just entered university after failing his entrance exams the year before. Relocating to Tokyo and looking for a place to live, he ends up moving in with Luna, an older relative on whom he used to have a crush. The Luna he had admired in the past had grown sophisticated and beautiful... and also slutty?! Night after night, he hears her loud voices, and it's making Naoto horny. Her sense of distance from other men is also extremely close. He is at the mercy of Luna, whose thoughts he can't comprehend. What's more, other girls with erotic proclivities besides Luna start to accumulate...!? It's the start of his exciting new life surrounded by slutty(?) older girls! (Source: Kadokawa, translated)