Is some of the gallery set to be released in chapter 2? I cant seem to unlock the last image for Kousuke or anything for Ryouko or Mika
all the gallery that had thumbnail in it is released in chapter 1, if you can't open it or it is still blurry, it's mean you arent open the route yet... if you have finished the chapter 1 but you didnt open that gallery or H scene route, it's because your love stat of that character isn't enough to do the route. You can check the walkthrough about how to go in H scene route for each character
For Mika, every meet with her, there will be some choice that will add your stat or not, you can try to chosee one and rollback if that choice isn't the right one. For Ryuko, it's more complicated, you can read the detail of the character on character list, what she like and dislikes. That will help you choose the choice... When you get the right stat, ryuko will ask you to come to her bedroom.