Yuka Kaori

Your grandpa sends you to his manor in the countryside. There you're introduced to a beautiful young woman wearing a flower print yukata.

"My name is Yuka Kaori" She says "I'm Doe-sama's mistress."

You're surprised to learn your old geezer grandpa has such a beautiful young mistress. Guess being filthy rich and connected to the imperial family has its perks. You wonder how your grandma would feel about her husband sleeping with such a young woman "Does grandma know about you???"

Yuka answers "Yes she does. Its very common for rich and powerful Japanese men to have a main wife and unofficial mistresses. Its a tradition going back to the Heian period."

"I see" It makes sense.

Yuka explains "Official wives look the other way because mistresses do the things they don't want to. For example, a husband can't ask his official wife to offer blowjobs or rimjobs because she is a woman of high social status. But a mistress is a woman of low social status and she serves her master however he desires including blowjobs, rimjobs, or shibari."

Your cock hardens involuntarily at the mention of those sex acts. They sound odd in the mouth of such a beautiful and graceful woman. You ask "How did you become my grandfather's mistress?"

"I was trained as a traditional geisha" Yuka answers "Geishas aren't like common whores. We don't have sex with common customers for money. We only have sex with our Danna or our patron and any man he wants us to entertain. Doe-sama became my Danna. He is a very rich and powerful man so I feel honored to be his mistress."

You feel curious "Has grandpa ever asked you to sleep with other men?" Yuka says "He has a few times. For example I slept with your father following Doe-sama's order."

This is news to you "Wait what??? I thought dad and grandad were estranged!!!"

"They were but Doe-sama sent me to your father as a peace offering and I managed to seduce him. We had sex many times in this manor after that."

You suddenly recall your father's business trips and realize they were excuses for your dad to come to the manor and have sex with Yuka despite being married to your mother.

Yuka says "You should know I've given birth to both your father's and grandfather's babies. Your half sister and half aunt. Do you want to be the third to knock me up???"