The Book starts off with Rei and Aria on their date, although their fun is briefly interrupted by some douche canoes from another academy that think it's "Pick on Rei"-day. Rei and Aria obviously clean the floor with them. We then learn that the whole team has done the very same with the best of Galen's ever since the break began. The other two teams get increasingly anxious and even team up to try (and fail) to beat the group. Then the break ends, and the team travel to the tournament. Some grand (pun intended) character development happens and they learn that a) their official team name is Firesong and b) that there's also douche canoes at the tournament. The resolution for b) is that Rei gets to punch the lead canoes lights out personally in quite the spectacular fashion which leads to the first major confrontation with the man, the myth, the legend(-ary a-hole) Major Reese.
But it turns out that Valera Dent has been granted field command, meaning she now is Riess' superior for the tournament and gets to make him look as dumb as he is. Rei also finds out that he can grow Shido even quicker at intentional disadvantage, because he had a major rank up against the clowns from fighting without Shido called against users with called devices. Grant has some more character growth. The tournament proper begins and all Firesong members do quite well in the Solo part. The Team Battle and Wargames go like a house on fire because literally everyone gangs up as soon as Firesong enters the field. Hilarity ensues with various team members going bonkers at various steps.
A lot of awesome fights and developments happen. Catcher gets a fancy new ability called "Ruinous" that is basically Overclock on steroids, delivering all the bang in one second without any drawbacks. Then Chancery gets "Warband" which turns her into the power puff girls allowing her to have two fake Chancery's confuse her opponent. Rei gets Aria and Catcher on board with the theory that Shido is influencing CADs in its vicinity. Aria calls it "infecting" just to be contrary and grosses everyone out. They decide that Viv is gonna be the final clue.
This is the part where Bryce yelled "Time for some Character Growth" and then Character growthed all over the book. Logan is super nice to Viv who is concerned about falling behind and being kicked off the team. Logan is overcoming his irrational hatred of Rei telling Viv nice things about him and Aria. They then have the dirtiest kinky sex you can imagine, but it's never actually described in the book because this ain't that kind of book. Go to R34 for that kind of thing dude... (And for god's sake don't google that...) Also use protection if you ever decide to do that.
Since everything was kinda fun and going well for Firesong Major Reese decided to do his job for once and messed up everyone's day. Turns out Firesong gets to relive their break performance, yay! But with two more enemy teams, boo. Naturally this makes Rei go super broody and depressed which Aria decides to be the best time to get him to an awesome place in the hotel with a great view of the city to have character growth and make out with him. They're now a couple and Rei swears that kissing games are not the only reason he's now in a better mood. They're out of the wargames but the team battle is basically theirs. And individually there's almost only Galen's users left with Firesong making up the majority by some margin.
Next wargame Viv has an absolute insane fight, because she misunderstood Logan and thought by "you need time" he meant "tomorrow". Naturally she ranks her CAD up but doesn't get an evolution and no ability which makes her cry and Logan panic. In that panic he calls everyone by their first names, majorly confusing them but also showing how he truly considers the team as his friends now.
Viv is defeated by a nice dude from Galen's, which leads Rei to absolutely "squirrel" all over him when they meet up next. I don't know what kind of squirrels they have on Astra 3, but they're probably something from an H.R. Geiger novel. He then character growths with Viv showing that he has learned that he isn't responsible for her emotional state and then also spills the beans about his kissing games with Aria the night before.
Firesong individually and as a team trounces everything and everyone. And we come to the final climax of the book. Aria vs Rei. I refuse to summarize this part because it's awesome, gripping and you should just read it again. The fight ends badly for Rei and he's hurt physically by someone hacking the arena. We learn that Aria's mother was at the tournament and had a sideplot about hacking the arena to give Aria's opponent a slight disadvantage. Also at the tournament is Arias brother, who un-effs the inane plan by blasting the evidence out of existence and thus saves Aria from her mothers idiocy.
One of the most terribly accurate tellings of waking up with severe trauma happens. Rei is brought back from his panic attack by Aria and Viv. The latter then complicates things by mentioning the suspicions the gang has against Central Command, which makes the Officers from Kenneth curious but Dent shuts it down with some ISCM classification stuff. They leave and their discussion about what happened is interrupted by the rest of the gang because Rei skipped a Rank entirely. Dent then gets a call because Central Command has noticed Rei got not one, but two new abilities. Rei and Aria have to overcome the trauma of the incident before, but then Rei is blown away because Aria also had a crazy evolution. He then calls his own CAD and he's now basically full body at C9. His abilities are now Typeshift: Phalanx Mode and a charged ability called "Temporal Step".
Temporal Step turns out to be an actual teleport ability same as the "Hole Drives" used for interstellar travel. This makes Reese wish he had brought the brown pants, he panics and throws a tantrum. Sadly we are denied having Captain Dent whoop his sorry ass to next Tuesday and he is relieved of duty and sent packing to the hotel. Dent then explains why everyone else should have brought the brown pants as well, but the gang is far too excited. She also forbids Rei from participating in the final team battle. The gang decides, after Rei strongly urging them, to actually do the final battle match.
Rei is left alone because the rest of the Gang has to go fight. He is set upon by Anatoli Sidorov who is being his usual psychopathic best. Christopher Lennon and his Girlfriend Candice "Dice" Meyer rescue Rei by barging in and sending Sidorov packing. Dice makes Rei understand the world of (figurative) pain he is now in for and that jealousy will be a constant thing he now has to face. He tells them most of what happened to him since the incident but fails to mention the overhaul Aria got.
Meanwhile Character growth happens in the underworks. A lot of. The Gang minus Rei has a heart to heart, Logan opens up, but is interrupted by the match starting. Aria asks the gang for 15 minutes of attention because it's important. They are called in. Aria has a terrible flashback and almost fails to enter the field. Rei begins a wave of encouragement that sees her over the line. The Gang then proves that Aria was being slightly dramatic with her request for 15 minutes of attention and finishes the match in less than 30 seconds.
The Tournament wraps up. Aria v Rei is deemed a draw and no winner is declared. The Gang finally makes it to the hotel, and Aria sends everyone away to eat. She and Rei cuddle a bit to overcome the trauma of the day. The Gang returns with food for Rei. Rei tries to start telling the Gang about Shido but is interrupted by Logan wanting to talk first. Logan becomes an actual human being with a character background to make the most broody and edgy DND rogue jealous. Afterwards they hug it out and then Rei tells everyone he has S-Ranked growth. Which makes Chancery and Logan go bug eyed. They get to ask questions that no one in the room has any answers for and then go to bed.
They leave the hotel, except Captain Dent gets to tell Major Reese to get effed by authority of everyone having it up to their eyebrows with him. We learn that Reese isn't just an idiot but also a coward. We also learn that Viv is nuts asking Dent for a favor. The Gang returns to Galen's and now gets personal poundings from the instructors almost daily. Aria and Rei are called in to Administration, where Carmen Laurent awaits. He's been tasked by Shira Abel to put the pressure on Firesong as a whole. Rei figures out the dissembly and they opt into the challenge. Firesong now has to win, as a team, against the strongest teams in the entire ISCM. They leave and Carmen accidentally lets slip to Rama Guest that the world is ending. He then sends Rama away only to call Abel to tell her where she can stick it in the future. That done he calls his wife and we learn that she is basically for him what Aria is for Rei.
Rei and Aria meet Viv sneaking out, but character grown Rei decides to let it go until tomorrow. They then decide that they'll spend the night together (yes, probably like that, but again, not that kind of book). Later that night Rei sneaks out to call Jasper and reveals that he figured out he's a Kamiya family member. He forces her to sponsor the entire team and not just Rei personally. We learn that one of the people who are about to become Firesong's trainers is none other than Kalus Laurent, Arias brother.
The book ends with the revelation that Viv has spent the entire week battling against high ranked simulations every night. As a means of trying to force her development. She then decides to ramp up her opponents from the already too high into the mental/suicidal territory in the S ranks. She gets her ass handed to her repeatedly until she finally ranks up, has an evolution, gets an ability called "Endwalker" and then passes out due to probably brain damage.