A new chapter in a tropical night! It was a summer about three years after I, the second son, married Nanami. My older brother, who had left the house saying he wouldn't take over the family business, returned to the sound of the cicadas chirping. Ever since then, my wife's behavior has been strange. Although I didn't think my wife was doing anything strange, I got worried and set up a camera to record her while I was away. What was captured on camera were beads of sweat, shining lips, and hair sticking to her skin... My older brother was lusting after my wife, and although she resisted, she gradually accepted and began to have sex with him. The wife I trusted...