That text on her phone from that other agency is a bad prelude. They probably had cameras in their office and are about to blackmail her. I hope sequel isn't NTR.
Blackmail and whatnot seems a bit of a reach. Nina literally told Nikaidou about that text/email before they started banging, and afterward admitted that her "plan" to sleep with another producer was just a ploy to get Nikaidou to make a move. And the message itself remained unread. I agree with Zeldafan, I think the point was to focus on the photo and emphasize that she doesn't really care about anyone else.
I'm surprised so many people interpreted that unread text at the end as a "bad sign." All of that was explained before they had sex (when Nina teased Nikaidou about sleeping with a producer to get an audition and getting an email), and was resolved afterwards (when Nina admitted that she was joking, as it was a ploy to get stiff-ass Nikaidou to finally make a move). And the message itself remained unread, next to a cute photo Nikaidou, which I thought symbolized that he meant more to her than the message she ignored.
Very interesting style. I really like the heavy shadows of the backgrounds. The angles are really dynamic and interesting and the line work changes up, making the sex feel intense and visceral.
Super interesting and well done. I'm looking forward to more from this artist.