Just finished ビブリア古書堂の事件手帖 2, and it was a very nice read!
Very relaxing compared to other things I’ve been reading recently too.
It’s also nice to have protagonists closer to my age (even though they are still quite younger) instead of teenagers.
In terms of content, I was sucker-punched by the part on “a clockwork orange”.
Spoiler for the first chapter of ビブリア古書堂の事件手帖 2
For once, the mystery revolved around a book I have read already! Yay, I have a shot at guessing the thing, I thought naively.
Turns out the twist comes from the fact that, when that book got published in the US, publishers didn’t like the end and changed it!! The author reluctantly agreed to that due to external pressures. When the movie adaptation by Stanley Kubrick, which is obviously based on that version, became a hit, translations abroad basically only used the US version.
Apparently, recent translations in Japan are now based on the complete version. The fact that one character ignored the existence of that true ending meant that they couldn’t have read a new edition as they pretend they did. I also missed it, since the version I read was also incomplete 
Anyway, I also love the way the interactions between the two main characters are evolving. First book, she said she doesn’t trust him (but they somehow get back on friendlier terms in the epilogue); second book, she says that she doesn’t want to ever get married (which implies no relationship either), then in the epilogue she basically accepts to go on a date. Well, one step back and two forward? Still, I wonder where this will go.
Finally, this series is officially characterized as a light novel, but I felt the quality was much higher than other light novels I have read. I will definitely keep reading this series.
I’m also thinking to recommend it to the intermediate book club, but at the same time, I’m not planning to re-read the first volume Still, recommended to anyone out there reading this. 