Yes the author does porn of their own work, it's in fanbox (a premium paid subscription service)
I wasn't aware of this, but it doesn't surprise me. I've seen a few web-based manga artists publish the regular stuff on Twitter, but on Fanbox, it is like WHOA!
Edit: Okay, I paid the ¥1080 yen. The artwork is lewd for sure, but stops short. So Sakurai might be nude, but you never get to see anything. There might be an implication of her having sex, but again, you see nothing, and no partner. This would be pretty hot if it went all out, like the other works from other artist I've seen. As it is, the artwork will at best give one a case of blue b---s.
I see that after I paid, someone has a site reposting the Fanbox stuff. Well, I don't mind giving the artist some money. But if we aren't going to actually see anything, I'm not paying $10 just get get a lewd image.
I'm almost sure the author's fanbox porn is canon already for these 2 at least.
Meanwhile Futaba has yet to catch up to her fanbox "Hamster eating banana" porn art.
I never saw Kazama. Lots of Sakurai, some suggesting sexual activity in high school. Based on the artwork, Shiromanta wants to see Yuuto with a woman (Natsumi, presumably), but also wants to see him in BL buk--- situations. Definitely has a thing for Natsumi ravishing Futaba, but then men (not shown) ravishing Natsumi or Futaba, but not together.
Personally, I'd like to have seen some self-insert art where the girls actually have nipples, are nude, looking into the camera. That would have been worth the money.