Just finish part 2 of Bookworm.

If anyone is thinking of picking it up after watching the anime I cannot think of anything that changed apart from some extra details but I would still recommend reading part 1 and 2. If not at least read the epilogue of part 2 volume 4 and the side stories at the end.

The ending of part 2 hit harder than the anime and the side stories give a lot of extra details and insights into the other characters.