I like those comments about abusing genderswap features for smaller hitboxes to gain in-game advantages. That sounds exactly the kind of thing the protagonist would use at the right moment. I wouldn't be surprised if there's at least one chapter featuring that kind of cheesy strat.
For those confused about "thin books", this term, 薄い本 (usui hon, meaning thin book) is what the Japanese call the pieces of, ahem, cultural literature popularly known as "doujins" in the west. These are self-published by authors at a print shop, but it's a "thin book" because as some of you would know, these things typically only have < 30 pages per "volume". So apparently in this universe Kiira is popular enough to have plenty of these things, and most likely of the pornographic variety. That "bikini armor fundamentalist" in the (fictional) Anverse game company knew exactly what they were doing.