Plot-wise: Overall, I enjoyed the plot. The Yamamoto character was intriguing, and I was on the edge of my seat for a lot of the time. Unfortunately, I didn't like the main character as much - he often came off as whiny and immature. But perhaps that was the point. I also felt that it was a bit heavy handed and dramatic at times, when it really didn't need it. Kind of read like a Japanese drama (teary, epic monologues in the workplace kind of thing). So, maybe not so true to life, but the message was great, and the unfolding of the Yamamoto mystery was also well done.
Language-wise: This was a very approachable Japanese shosetsu - the writing was quite simple, with short sentences and a lot of dialogue. Some of the kanji were difficult, but it was easy to skip over them and get the general meaning.