A secret from my wife, JK anal training ~Teaching my wife’s little sister how good anal feels~ [Final] [Appetite]

Souichi used to fool around with women until he impregnated Sakurako.
A woman from a very distinguished family. With no way out, he had no choice but to settle down and marry.
One day Sakurako’s little sister, Kikuno, approaches Souichi.
Onii-sama, I have a very embarrassing problem. I suffer from insensibility, I’m sexual frigid, can you help me?. She says.
Souichi, having resigned himself to a life as a mere husband, feels delighted, “human resources” so close-by!
Kikuno is Sakurako’s little sister, she must have “potential”. Souichi thinks.
Souichi immediately begins training Kikuno into becoming an anal slave.