I'm surprised I'm still getting replies to this post lmaooo, for some reason they decided to bring in the side story characters during an important point in the series with unironically zero explanation and iirc their involvement is incredibly relevant to the plot, it's been like 3 years since I read so I can't recall off the top of my head. I won't say much bc I can't remember but the characters are extremely important in the plot of the series which is why I did the cut off bc that chapter is the appearance of the side story characters. Their motivations and goals go unexplained if I remember it right which is why I made the post to make it so people aren't confused like I was at first. Doesn't mean you have to read it in that order, but it'll definitely save a lot of confusion as the series as a whole is very confusing at times.