This author has a habit of making her side characters have personality too, even if they have no prominent role in the story. All the characters are so interesting you want to see them again and again.
The guy is that fanboy. He called him kai which is his stage name.
No he is not. If he was why did they have different hair colors. I mean if they really were I'd think you'd at least be explaining why their hair colors are different especially when that's been pointed out to you in the questions themselves...?
I don't think he's the fan boy. I believe there were 3 guys : the classmate who was Ikumi's first love (one sided and he was rejected) ; the black-haired AV actor who conforted Ikumi when he first was in a porn (Ikumi remebered him and just wonered what happened to him after the AV) ; then the fanboy who could have accepted his feelings and sexual orientations thanks to Ikumi's videos.
There was no black haired AV actor whom Ikumi met...? There was just the blonde haired former AV actor...?
The one that he was remembering was probably that dick Arinuma whatsisname.
Chapter 3. page 13-15 or 18-19. There was a blank haired actor. Ikumi wonders what happened to him and it's not the fan boy who is just a fanboy. And if he called him Kai, it's because it was Izumi's name as an AV actor.
The story was good overall, but I honestly thought the black haired stranger from chapter 2 whose probably the high school classmate from his memory would make an appearance to talk to him further in the story, but he never did.