Basically, volume one is from the protologue to the end of Chapter 1, volume two covers the whole Chapter 2 as well as Chapter 3 Daily life, and volume three is from Chapter 3 Trial to Chapter 5 Daily Life, and edns with the body exploding (Naegi suspecting it belongs to Kirigiri). The anatomy can be sometimes distorted and the artstyle is not as good as the Nagito one, but also pleasurable to read. The pace is a bit fast but all the main points (for reasoning and deduction) are included.