To get the CG in the top right corner of page 14 you need to let Hisami reconsider his actions on day 59 ("Have I been wrong the whole time?"). That's the "good ending" (dunno if that really is a good ending) with Hisami.
The second row of page 18 seems to become complete once you've seen both endings with Hisami.
The second row of page 18 are the cgs for the last date with Oki (steamy garage scene) and the last two are the cgs you unlock watching Hisami prequel story after you unlock it on a new game.
I'm currently missing the last two cgs of the third row of page 18 and the entire page 19, if anyone knows how to unlock the encounter with Dr.Ken it would be major because I'm sure I'm missing his cg
