Hiroki is Glen Schreiber.
- Hiroki may have been pretending to be Glen's brother Bart. She already pretended to be Veronica, so it's not inconceivable for her to pretend to be someone else.
- Hiroki can't use magic. Bart was of noble birth, but Glen wasn't and may not have been able to use magic.
- Other observations are written here
.- It's confirmed in chapter 33 that Hiroki isn't Bart.
- And it's confirmed in chapter 35 that she is Glen
Zeze is Prince Eugene.
- Zeze remembers Princess Veronica saying that she'll protect the castle. She did so in front of Eugene.
- Counterpoint: There were at least two others behind Eugene, who witnessed this as well.
- Zeze claims he doesn't remember who he is, paralleling Harusumi's ruse of hiding his identity as Veronica.
- Zeze repeats the exact words of Prince Eugene on what type of girl he prefers. Only Vince (Teshimano) was present.
- Appears to be confirmed in chapter 28.
Zeze is Lucas Erlanger.
- Zeze is easygoing, as Lucas also appears to be.
- Appears to be disproven in chapter 28.
Nishina is Prince Eugene.
- Nishina is Ashley, who may be the Moswick knight that Cotton (Nanaura) killed. Knowing that Ashley died by a physical wound, he's free to act as Ashley.
- Counterpoint: Nishina is in Nanaura's group, who does not call him out for this.
- Appears to be disproven in chapter 28.
Nishina is Lucas Erlanger.
- Lucas seemed to have been used by Prince Eugene, so Lucas may have joined Nanaura to get on the inside of Eugene's group.
- Nishina knows about recovery magic, which people other than priests didn't know about. It also can't be used on one's self, so it makes sense that he asked Maki to do it.
- It's theorized that using recovery magic on non-priests causes loss of magic. So we may know if Nishina is Lucas if Maki can still use magic in the future.
Kamioka is Prince Eugene.
- A classmate in middle school casually asks "If Minami was a princess in previous life, was Kamioka your prince?"
- Counterpoint: It was a comment made casually by a third party.
- Appears to be disproven in chapter 28.
Kamioka is Glen Schreiber.
- Kamioka's relationship with Minami Harusumi is like that between Glen and Veronica, close but platonic.
- Counterpoint: Kamioka is not in Harusumi's class.
- Disproven in chapter 35.
Nanaura is Lucas Erlanger.
- Nanaura doesn't have an alibi when Kamioka was attacked.
- Counterpoint: Nanaura and the perpetrator were thought to have worn different clothing at the time.
- If Nanaura was responsible for the attack on Kamioka, he is hiding his identity as a priest.
- Counterpoint: Another person in his faction—possibly the leader—could be a priest.
- Nanaura claims to have fooled Harusumi and Hiroki after they were convinced of him being Cotton after questioning him.
- Counterpoint: When Maki remarks that he's not actually Cotton, he appears to deny the notion.
This is going on elsewhere.
Class 4 isn't the only place this is happening. The "past world" was a place where wars were fairly common, and it wouldn't be unheard-of for large numbers of people to have died over time to some kind of magic or another, and thus forced to reincarnate on modern-day Earth. But the majority are those without magic, and probably illiterate peasants too, and so there have been few opportunities for anyone awakening early like Harusumi to trigger anyone else's awakenings. But things have been heating up in the past world, and there may be a bit of San Dimas Time going on with times then and times now linked together, meaning more magic-users and literate people have been dying to magic, making more opportunities for someone like Harusumi to come around and accidentally awaken the others around them. Or it may just be that Harusumi is special in awakening early but some of the recordings of magic and past-world writings have spread and started triggering other people across the world. When the major mystery is solved, it will turn out that this was just "part 1" of Bokura no Kiseki and the characters discover they're part of a whole world newly awakened to past lives and magic. It's going on elsewhere and it's an invasion.
The past lives are taking place on another world, one that's dying. The betrayals and murders via magic, and thus the forced reincarnations such as happened with the people of Veronica's castle, are part of a great magical working by the church to cast a seed of their world forward into another. The church had to cooperate with the nobles to get it done, mostly out of necessity - they needed more people with magic than the church had, and that pool of talent was composed entirely of the nobility. But very few people would agree to actually be killed like that, so the high church elders conspired with the most powerful nobles and royals to make it happen under the pretext of war. And now, after escaping their world, they intend on recreating the old order with the aid of their fellows who are now effectively "sleeper agents" reincarnated around the world, taking the seats of power across Earth and using magic to enforce their will.