Kaori is working at an AV (adult video) production company—not as an actress (at least not yet; who knows what the author will do)—but as a staff member. You may be wondering why, and the answer is simple: because the author wants it that way. According to Kaori, she’s working there to gain experience, but it makes no sense for someone who wants to be an idol to get involved in AV in any capacity. You can try to rationalize that the AV industry is a microcosm of the entertainment industry and that it can serve as experience, but that’s nonsense. Idol and AV don’t mix.
Yoshioka is working as an idol and an actress. In the most recent chapters, it was revealed that after Kaori broke up with Hidaka, Yoshioka and Hidaka are apparently dating. I say “apparently” because we don’t know for sure yet, since we’re in the middle of a flashback about what happened after the breakup. I have no idea why the author decided to do a time skip only to immediately follow it up with a flashback. Why not just follow chronological order? And to make things worse, the time skip introduced a new character right at the start, leaving everyone confused. It’s just straightforward bad storytelling. A short time skip followed by a flashback makes no sense.
Hidaka failed his medical school exam and is studying to try again. As I said, he’s apparently dating Yoshioka.
Mangamusa must be confusing Yoshioka with Saori, who is a porn actress and was introduced at the beginning of the time skip, leaving everyone confused. Her motivation for doing porn is as absurd as it gets. She’s an educated woman from a distinguished family who feels repressed by them and is doing porn to be disinherited and avoid an arranged marriage. Her plan? For someone to recognize her as a porn star and inform her family. Run away from home? No. Get a job and become financially independent? No. Make porn in the hopes that her family will find out? YES.
That’s all that’s happening in this dumpster fire.