Three days have passed since my wife left the house after a trivial argument. With a rare large typhoon approaching, I was already feeling more worried than angry. A few hours later, the doorbell rang. I suppressed my excitement and opened the front door, but it was not my wife but her sister, Tsubasa, standing there soaking wet. She had come out of concern for me, but I couldn't take my eyes off her shiny wet hair...rainwater dripping from her jeans...soaked underwear...