For a story featuring a main character whose family (who also form his "harem" in a way) are stolen from him, I would argue the
Henteria series excels most regarding its writing and scenes. The series revisits narratives involving the step-mom and step-sis being taken by a bull/bulls. A caveat, however, is that the protagonists does not engage in sexual scenarios with their "sisters" or "mothers" within the series.
As an additional recommendation, though unrelated to suchlike family dynamics and a bit distinct in tone,
A Promise Best Left Unkept (+
Aya Edition) may be of interest. Laura, the main heroine, is a strong-willed career woman akin to Kyoka, while Aya shares similarities with Yuika's character archetype. And the antagonist is an epitome of a blonde blackmailer-womanizer.
If you're seeking similar artwork featuring slender, statuesque women + a stepmother&stepsisters harem dynamic, I would actually recommend a couple of pornhwa. But these are predominantly netori narratives with some ntr elements.
You might also be interested to visit this couple of family-ntr threads: