please use quotation marks, what the fuck, man. Okay the first thing I see is overexplaining to the reader things like character's names and their appearances, etc. etc. but the thing with fanwork is this: we already know and we don't care to read it. It's a pain in the ass, to be frank. Drawing attention to certain details indirectly or as a part of an action is much prefered. Also having a character go through a thought process only to tell the reader "but that doesn't matter now" doesn't work at the beginning of a story--it makes the reader think "if it doesn't matter, why are you telling me?". (Though such thought processes can work later in stories after the readers are invested in the character and the time is appropriate.)

Listing the dialogue is a huge issue. It reads like a screenplay and gives the characters no soul at all. It makes them feel like robots and it takes the reader out of the story. During long spans of two characters talking, it's very easy to lose track of who is saying what. Another thing(that seems to be common among budding writers) is the excessive use of commas. Stringing a long thought process together with only commas and no breaks is difficult to read and makes the writing look spastic. You should slow down and space the thoughts apart, give the reader room to breathe.

The second section also suffers from "telling us shit we already know" syndrome, most obviously with the phone call between Satori and Keine being repeated not even five lines after we just read it the first time. Less obviously, the narrative tells us that Keine looked thoughtful, and then moments later Mokou points out that Keine looked thoughtful. Reusing the same things so quickly feels very uncreative, and like the phone call was just copy/pasted again to make the story look longer.

The characters also act a bit odd. Such as Satori stating her full name and position to someone who already knows her(as shown with "It's been a while"), it comes off unnecessarily rigid. Any reasoning I try to come up with to explain why she would so awkwardly introduce herself to colleage in such a manner(such as she feels uncomfortable or unsure that Keine remembers her, or maybe because she's just super professional) ends up conflicting with her pointed and direct questioning at the meeting(where she shows no signs of feeling uncomfortable or professional). Also I fail to see how the occasional quip means that Satori is "unable to keep quiet".

But the one thing that legitimately, genuinely pisses me off about this fic is the thinly veiled relationship between Keine and Mokou. It fills me with Erebus levels of rage(which is why I'm so glad you're here for me, Iced). First the line "Mokou, trainee at Gensoukan was in the middle of a discussion with her responsible teacher about a subject that will go unspecified for the time being" just reeks insanely of TEE HEE HEE LESBIANS, and that's ignoring the "if it's going unspecified WHY ARE YOU TELLING US ABOUT IT AT ALL JUST MOVE THE FUCK ON". But because Keine and Mokou are shipped by a large portion of the fandom means that they ABSOLUTELY MUST BE HAVING GAY SEX IN EVERY FORM, right? And then Satori -makes a joke about it-, like a fellow teacher shouldn't be worried about a teacher-student relationship, let alone a gay one(which, in case you haven't noticed, is a gigantic issue in the contemporary world).

The sheer need to slam every Touhou up another one's ass displayed by some people utterly baffles me. There's nothing wrong with just having them be fucking friends. And even from a relationship perspective, it could have added some tension or substance to the story, the hidden, forbidden relationship between a teacher and her student. It could have been a nice subplot in many ways, both light and tense. But, no, you just wanted more gay toohoos in your fic and that's literally the only reason they have that substanceless relationship. People like you are why people like Erebus exist, and why people like me can't openly talk about various ships without being looked at like we're retarded. Thanks.

Next time you write you should just not do it because fuck you.