It's the day of Kirin joining Sensei's class, which, according to Maya, is also something that never happened in any other cycle. Kirin introduces herself to the class, though only out of courtesy since most of them already know her from the Christmas party, and Sensei is surprised that her introduction is pretty normal, having expected her to cause chaos during it. She offers to answer any question the class may have, but when no one raises their hand, she takes her seat at the unoccupied table next to Io. Kirin immediately tries to bond with her, but Io rejects her attempts in her usual manner, which just makes Kirin even more interested in her.
Suddenly, Wakana storms in, being completely fed up with the anarchist in her class and demanding that Sensei lets this student transfer into his class immediately. The girl in question has followed her, chastising Wakana for abandoning her during an argument and her duties as a teacher, but she falls silent the moment she notices Sensei. She starts tearing up and asks him where he has been all this time before she hugs him tightly and cries into his shirt in front of everyone.
Sensei, who assumes that she's someone who was very close with the original Sensei, asks her how long it has been since they last saw each other, and she informs him that it's been three years, that he already disappeared before that, and that she never abandoned hope that she would see him again. Realizing that there's no easy way out, he decides to tell her about his amnesia and promises it isn't just a convenient excuse to dodge accountability for ghosting her. While the girl would've liked some compliments on how much she has grown during his absence, she believes him, being perfectly fine with them starting over and making new memories. Sensei thinks that he should know her name in that case, and she introduces herself as Noriko Nakayama.
Sensei notices Ami being in tears and raising her hands, wanting to know who she is, but a loud bang catches everyone's attention – Maya slammed her fist on the table and is unusually hostile and aggressive. She demands that Noriko leaves immediately, but when she doesn't react to it, Maya walks to the door and leaves herself, but not without stating that Noriko "was unwanted then and is unwanted now" and how no one will ever love her in any timeline, which Sensei takes a mental note of.
Sensei asks Noriko why Maya would act so uncharacteristically hostile, but Noriko can't remember what she did to her and only knows that she always acts like this towards her. Seeing that she's now a student in his class, she formally introduces herself and tells the class about her interests, which manages to catch Kirin's interest.
Noriko joins Kirin, and Wakana files an emergency transfer so Noriko will officially become his student. While him getting another girl would usually be a good thing, Sensei can't be happy about it considering the chaos and discomfort Noriko's appearance caused. He's also worried about Maya and her outburst, but he can't find her anywhere when he tries to find her after school, and the day comes to an end.