My friend's wife is a lewd tutor

Taniguchi, whose family was poor, gave up on going to college and started working right after graduating from junior high school to support his family. Eventually, Taniguchi became an adult and was able to afford his family's finances, and was thinking about taking the university entrance exam and pursuing his dream of going to university. However, when he was at a loss because he did not know how to study, his friend's wife happened to be a private tutor and she decided to help him study. Then, I asked my friend's wife to show me how to do it...