I got a job in my hometown and moved back to my parents' house, where my turbulent days began. The biggest change was that my parents remarried and I got a younger sister. On top of that, my father was transferred three months ago, so my sister and I were left behind in this house. My younger sister, Hina, dropped out of college and has been staying at home ever since, but when the air conditioner broke in the middle of summer and she saw me covered in sweat, her hidden sexual desire exploded and she jumped on me, saying, "Big brother, can I just borrow the tip!"...