At around 18:30 in the 1st episode of Domestic Girlfriend, when the MC is asking for advice from his friend, there is a shot of some books on a shelf:
As the well-known novelist Anton Chekhov put it,
If in the first act you have hung a pistol on the wall, then in the following one it should be fired. Otherwise don't put it there.
I suspect that (most of) the books in the shot have something in common, which in fact indicates the route of the whole (or at least part of) story.
Unfortunately, I don't know about these books, let alone their contents, and therefore I can't figure out the meaning of their appearance. However, one thing is for sure, if these books have nothing to do with the plot, the producer wouldn't have bothered to make such a special depiction.
What significance do these books have?