Chigusa, who had been married to Kenji for a year, was living happily. As her wedding anniversary approached, her husband consulted her about letting his brother Kazuhiko stay with them while he looked for a new job. To make matters worse, her husband decided to go on a business trip, leaving Chigusa to spend the anniversary with her brother-in-law. After seeing her husband off, Chigusa thought she had gotten close to her easy-going brother-in-law, but Kazuhiko became aroused by her unguarded appearance and pushed her down. Since that day, the physical pleasure etched into her body kept replaying in her mind…
