The core of this keyword string rests on the Japanese term Yokorenbo (横恋慕).
"Yokorenbo: Immoral Mother" is a two-episode hentai anime OVA (Original Video Animation) released in Japan in 2009. Its title can be translated as 横恋母 , which means "a forbidden love for one's mother." This name captures the series' main theme of incestuous desire, making it a notable example of taboo storytelling in adult animation.
Miki is Ryouichi's elder stepsister. She harbors a secret lust for her own father, a weakness that Ryouichi exploits to blackmail her for sex. Her route in the visual novel presents a more nuanced and even healing narrative, where two broken people find mutual understanding.