Female teacher who was seized into a slave soapland 12

Shiori's older sister, Kaori, was a teacher at a school where her father serves as the chairman of the board, but committed suicide just before marriage. The following year, Shiori inherited her sister's wishes and became a school teacher, but she falls into the trap of Onizaki, the father of Natsumi, a dropout student in her class and the soapland manager...