How do you get the 10th CG (The first one on the second page)?
Alright, soooo, you have to wait till after Tocchan shows you the photo of him in highschool (The one in his year book of him giving his school council president speech). After you get that scene and CG, buy the black looking school outfit from the bear in the love hotel (I don't remember the name of the costume, I think it started with a G? Either way, it looks exactly like Tocchan old school uniform in the first CG I mentioned). Just get him to ear it during foreplay after you've done all that and it should trigger. I should say that I triggered this one while Tocchan was a dominant top, so this scene is a different version of one of the scenes I haven't gotten yet (As the scene I haven't gotten yet needs him to be a submissive bottom when the costume scene is triggered).
Hope that helps!
I'm also really late since I haven't checked Itchi in ages XD It's been a bit since I played the game but I believe it would still work since it's just requirement triggers. Although, you've probably already discovered this yourself since it has been a year since you posted this according to the time stamp, lol.