So I did Damon's route until the last episode which is 8 until further notice. On the first page of his gallery and all the way to the 6th box, I'm missing one of his CG's and I don't know how to achieve getting it. If u don't mind letting me know which chapter and choice I have to pick to unlock it then that would be great!

I think that should be the CG of Alisa and Damon, so when you're playing Episode 4, choose to eavesdrop on their conversation and you'll get the image :)