Koushoku no Chuugi Kunoichi Botan

Botan is a kunoichi whose wedding approaches. Her uncle, a financier, asks to borrow her to aid a declining samurai estate and her own master. She accepts, viewing it as a mission. Following his orders, she conceals herself from her rightful master. Her small frame is then violated. Despite her rational view of the duty, her body reacts uncontrollably to the pleasure.