Hey everyone. The reason why we are having so much trouble getting Achievement 18 [the one under I Saw It (2)] is because of a programming error. The achievement is I Saw It (3), which you get for finding Maki (the blonde one)'s secret scene in a photobooth, but unlike the other "secret scenes", it doesn't have a trigger for the achievement. I added in an trigger for Achievement 18, and it worked just fine. Maki's is the only one without an achievement trigger, instead it has a "performance trigger". I think this is a mistake on the dev's part? Once you have Achievement 18 and all the others, the first achievement unlocks, as well as the last images in the album.
For the record, I found Maki's scene beforehand and didn't recieve an achievement for it, which is why I looked into it.
I searched the rest of the game for any other Maki events that would unlock the achievement, but couldn't find any, leading me to believe this is the problem.
pictured below is what is coded in currently, vs what it should say to make it work.