The brilliance truly came when YandereDev gave an unusual description of his game on Reddit during a discussion about tropes it's a classic Dating Sim or harem anime from the perspective of a background character who has gone utterly nuts and hijacked the narrative.
Why is Midori Gurin part of the Gaming Club? Because she is used as an Audience Surrogate in the developer videos.
Why does Midori Gurin's profile info talk about how she regularly asks stupid questions? Because she did that in the videos from YandereDev.
To drive the point home, she now stands on the roof while texting someone (presumably YandereDev), muttering to herself about pointless questions she wants to ask him.
Midori manages to stump YandereDev by asking why the students would keep attending class when Yandere-chan is slaughtering them left and right. He throws the MST3K Mantra at her, but there's a legitimate reason: education is serious business in Japan. If you're a student at a posh upper-class school like Akademi, unless you are hospitalized, your parents expect you to go to class no matter what, so you can get good grades and uphold the family's honor with your presence. Those kids probably want to stay home very, very badly, but their parents are forcing them to go to school. The parents might be worried about the serial killer, but they're more worried about the family's reputation if the child doesn't attend, and Japan has a severe problem with putting family honor above a child's well-being.
YandereDev also stated that if a student sees Yandere-chan committing murder, they'll keep going to school because they want to catch her in the act.
Which itself can work as more Fridge Brilliance. They are ALL acting like anime characters with no sense of self-preservation!
It may strike some as odd that, as Yan-chan damages a fellow student's reputation, that student becomes the victim of increased bullying, up to and including a flower being placed on their desk (a loving tribute to a student who passed away, but practically a death threat against a living student) and threatening graffiti written on their desks, and the teachers don't seem to be addressing the issue. This actually extends beyond the school administration's habit of sweeping anything that would draw bad publicity under the rug: Japan does have a fairly bad bullying problem, and there are many reasons a teacher may not try to intervene whether it's a belief that School Bullying Is Harmless, a desire to not worsen the problem by drawing attention to it, a belief in the good of the whole of the class or school above the needs of an individual student, or fear of jeopardizing one's career.
The dev has stated that while every NPC (except Senpai) you meet at school will be mortal and possible to kill, Info-chan is going to be present on campus but impossible to directly interact with. She knows she's working with an unstable potential sociopath who may be prone to violence, and doesn't want to be anywhere within sight of Yan-chan, just in case the girl decides to go on a random killing spree. Keeping the phone line between them is safe and smart.
Sure enough, she's in the Info Club room, which is locked from the inside with the curtains drawn and the lights low so no one can get to her or see her. And there's a CCTV camera positioned right outside so she can't be taken by surprise.
Reading erotic fiction levels up Yan-chan's seduction stat. Why? Because she lives in exactly the sort of Troperrific world that mirrors fiction even its own. To her, hentai is as relevant to actual sex as the Kama Sutra.
Some have noticed that even during low School Atmosphere, Budo Masuta is the only student who doesn't shake in fear. Of course he wouldn't. He's just that confident in his abilities.
Unless the Martial Arts Club is disbanded due to low members. Then he does shake in fear, probably because now he knows that his own tactics, which he taught to those that disappeared/were killed, are insufficient to protect him. He'll still take you down if he sees you kill someone, though.
The Undertale reference in one of the rooms is just for fun, right? Until you remember that YandereDev has said that Yan-chan's personality in the ending will change depending on your gameplay style. She can be a Serial Killer, a Manipulative Bitch, or a girl who has a few darker traits but is otherwise innocent. A large part of the premise of Undertale is that you can, and are in fact encouraged to, do a Pacifist Run. If you kill everything in sight, however, you'll play as an Ax-Crazy genocidal maniac who has no qualms about destroying the world. So a game where it's up to the player to decide how horrible the protagonist is references another game where it's also up to the player to decide how horrible the protagonist is. Well played.
Why is Ayano's mom, Ryoba Aishi, such an Open-Minded Parent, given that Japanese culture tends to look down on lesbianism as a "passing phase" and Yan-chan winning a female Senpai would mean the end of the Aishi family line, which is Serious Business? It's because Ryoba understands how deep and intense Yan-chan's feelings for Senpai are. As a yandere herself, she understands all about the sheer intensity of Ayano's feelings, so she accepts that trying to stop her daughter's crush is pointless, assuming the idea even occurs to her.
Word of God states that Ayano's father would not be as receptive to her falling for another girl. But then of course he's not a yandere.
The behavior the Student Council President has before launching into her speech (asking if someone's there, then going "Ugh, it's you") suggests it's a stream, rather than something pre-recorded. Her using a webcam rather than appearing in person may be how she's doing her duties, even though she isn't attending school.
Midori's status as The Ditz makes sense considering that she just stands on the roof all day and never attends class.
On the other hand, Mai is just as sexualized, maybe more so. Her breasts are just as big as Kokona's and she has a more stereotypically alluring hairstyle. But she's a Parody Sue and a massive in-joke.
What's the Gaming Club's benefit? Temporarily level up one skill per day based on game played, whereas Yandere-chan would normally only be awarded half a skill point per day (a full skill level can be gained if you go to class wearing the fundoshi). Who is this useful for? Speedrunners, ofcourse.
Info-chan's secret about Kokona is a video of her selling used panties to boys. She's desperate for money to pay off her father's debts, so she would naturally do anything she had to to raise some. Doubles as FridgeTear Jerker considering you can use this information to get her in trouble with the school, like it wasn't hard enough for her.
Doubles as Heartwarming in Hindsight, but why would Kokona respond to the domestic abuse note when she isn't actually being abused? Well, "Internet", "my feelings", "drug addiction", and "low grades" seems a bit random. "Anime", "manga", and "video games" would only be a painful reminder of what she could not afford. "Pregnancy" might come off as somewhat cruel, and "bullying" could be interpreted as accusing her of bullying. So why that one? She might have thought that someone was seriously in danger, and decided to meet up with them. That's right; she was worried about you. What a nice girl!
Because the cutscene was so significant, the "Betray/Befriend" build was delayed to June 1st. However, the actual contents of the build was actually timed well, since it focuses on Kokona's and Musume's fathers. What holiday takes places in June in the U.S.? Father's Day.
In a Meta example: Info-chan and Midori Gurin are (likely unintentional) foils to each other, their character designs being polar opposites. One has short red hair, offers crucial gameplay mechanics, has been planned as a main character since the beginning, has mysterious motives and dirt on almost every single student at Akademi; she knows everything; she's unscrupulous but useful, and impossible to kill. The other has long green hair, was a joke character created to mock fans who kept sending YanDev stupid emails, was put into the game as a minor NPC on a whim and became a Breakout Character, and is a flat stereotype known for constantly annoying classmates and teachers with stupid questions; she knows nothing; she's innocent but useless (she doesn't even have a proper routine), and is the easiest character to kill.
Why doesn't Yan-chan store her contraband in a bag or satchel of some kind like the one Kokona uses? Aside from the risk of teachers searching it as School Atmosphere drops, having a bag would make her vulnerable to exactly the same framing she victimizes Kokona with.
Word of God says the inspiration for the Basu sisters came from his desire to have a manzai dynamic in the game. However, they aren't the only people with that sort of relationship. The way this particular form of comedy works has the "boke" act silly and foolish, only to be berated by the more serious "tsukkomi". Soundfamiliar?
Just how crazy Yan-chan is becomes highlighted when you realize that the plot could be resolved within a week. Senpai is a Nice Guy, a bit of a pushover, and is willing to get love confessions from all kinds of girls. The only kind of person he'd outright say no to is someone who is a "bad kid", and even that's a stretch, what with the Delinquent Leader. In theory, Yan-chan could easily win Senpai by befriending him, asking him out, and then confessing her love. Y'know, like the Rivals do. Even Oka is apparently capable of this. However, because Yan-chan is a Yandere with an unhealthy mindset, she just can't do that. So she resorts to murder and manipulation, rather than the normal, simpler option like the Rivals. It explains the difference between how Senpai has different reactions to Rivals and Yan-chan in similar scenarios when you think of it like this.
Prior to the Matchmaking update, some people realized that pairing Kokona up wouldn't save her family from loansharks. The update itself actually addresses this: her suitor is the Secretly Wealthy (or so he tries) Riku Soma, who at least in theory has the ability to step in and help her out. So matchmaking Kokona does help her solve her problems.
Kizana compares her love for Senpai to Romeo and Juliet. This could be a simple case of kids not always remembering that play is a tragedy until you remember that Kizana is a rival to a Yandere. That relationship can, and most likely will, end in tragedy.
Senpai being generic actually makes some sense narratively, aside from poking fun at stereotypical protagonists in dating sims and romance anime. Word of God suggests Yan-chan's love may not be truly romantic or sexual, but more like "seeing color in a colorless world." She also flat-out declares in the intro that "Senpai will be mine. He doesn't have a choice." In other words, Yan-chan (who we play as) doesn't fully see him as a person, but more of an object that makes her feel good. Senpai could literally be the most interesting person in the world, yet she would never care about his feelings, hobbies, family, background, or anything. To Yan-chan, that will never matter. All that matters is that she has him. His being generic, down to his name, only highlights this.
Why is Yan-chan so dependent on Info-chan and manga for ideas on how to carry out schemes? People with alexithymia (a dysfunction in emotional awareness) are often unimaginative and would need something/someone to give them ideas.
The reason why Yan-chan is unemotional and pretends to live a normal life? Her father was abducted by her mother and forced to love her. That takes away any normalcy that she could have in her life. Also, judging by her father's voice in the later tapes, he is completely broken. He is emotionally dead inside, thanks to Ryoba.
It's more likely that along with the Yandere gene, the Aishi bloodline has a long-standing history of Antisocial Personality Disorder (formerly known as sociopathy and psychopathy).
Here's some Fridge Brilliance that actually goes out in real life that highlights the bathroom elimination method via wet rival and unscrewed electric socket. Who here has an outlet in their bathroom that won't function/conduct electricity unless the light in their bathroom is on? It's to prevent someone who is wet from accidentally touching it and electrocuting themselves in their search for the light switch in the dark!
The Four Gods Symbolism YandereDev used for the Student Council works perfectly not only for the four girls already in it, but also unintentionally for Megami. Consider this: in the Chinese version of the Four Gods, there's the Blue Dragon, Vermillion Bird, White Tiger, and Black Tortoise. However, there is a fifth god that is above them and is the center of the Cosmos known as the Yellow Dragon. Although Megami doesn't have yellow in her design, the description of the Yellow Dragon still suits her as the Parody Sue that she is.
This can also correspond for Ayano as well, if we use the Japanese version instead. In the Japanese version of the Four Gods, where each of them has an element, the fifth element doesn't have a corresponding god. That element? Void, which has connotations to emptiness, hollowness, and nothingness, which Ayano has felt in spades. Though it can also be read in the context of "Sky" or "Heaven", which represents creativity and spirit, the former being expressed in the many ways she can get rid of rivals, and the latter being what she wishes to gain by claiming Senpai for her own.
Chojo being part of the Occult Club may just be a reference to Makoto's dealings with the supernatural until one remembers one of his nicknames in the Japanese fanbase was Kitaro, the name of the Ghost Tribe boy who was born from and lived his days dealing with Youkai. The fact that his original series was also the Youkai manga in its time (and even helped respark interest through its many adaptations) doesn't hurt either. If Chojo has some of Kitaro's character, the kid's practically overqualified to join the club.
There might be a specific reason for the use of the Makeup Is Evil trope, considering how the only female characters to use excessive makeup so far are the Bullies and the Basu Sisters (who, while probably not evil, are rumored to be supernatural). Well, that's because a lot of real-life Japanese high schools are pretty damn strict and ban the use of makeup, nail polish, and the like; so it's probably used by these characters to show they don't really follow the rules, especially Musume and her posse.
Info-chan's "currency" of panty shots is rather bizarre for an apparently Asexual character, especially considering her role. But it makes sense because she deals in secrets, and underwear is something you want to keep secret. In addition, panty shots are relatively easy pickings when every girl wears a mini-skirt; Info-chan accepts them as a more consistent source of "income" until she can trust Yan-chan with surveillance bugs, which are riskier but much better sources of the secret information she craves.
It is also a Stealth Pun/euphemism, as 'secret' is occasionally used as a euphemism for underwear.
The teachers all apparently have basic combat training, forcing you to get your own if you want to escape being caught by them. Turns out Yan-chan's mother went to the same school, and perpetrated her own crimes there. After that, of course self-defense would be required for the teachers!
Given the way Yandere Simulator's world operates, it makes sense that the last rival of the game would be the leader of the student council. Who else would have enough clout within the school to make a suitable and narratively-satisfying Final Boss?
One of the manga series Yan-chan can collect is Youkai Story, a horror comic. What does it matter? Well, reading it boosts her "Numbness" stat this lessens her sanity loss after committing murder (or dismembering a body). Yan-chan is already a sociopathic Blank Slate, so what exactly is in those books to make a girl like her care even less about murdering someone?
Word of God says the chemical Yan-chan uses to poison her classmates' food is barium acetate, a chemical that can only be found using a machine Buraza Town doesn't have. Symptoms of barium poisoning through ingestion include nausea, diarrhea, muscle weakness/paralysis, abdominal cramps, vomiting, respiratory failure, heart problems, and kidney damage (see here and here). Remember this the next time you see the choking animation.
You know how when you successfully gossip about Kokona online, the rest of the Rainbow Six comment on the post with scorn (or disappointment, in Saki's case)? Notice that Yui is the first to reply by mentioning that she saw Kokona too. This may not seem like much, but remember Yui's persona happens to be "Evil", while the others are Social Butterflies. It's entirely possible that once Yan-chan initiates the bullying, Yui is the main one encouraging the group to exclude and bully Kokona, possibly For the Evulz. Ouch.
Think about the relationship Ayano's parents have. Her mother is a super-Ax-Crazy Yandere who ruined a man's life and is hunting him down now, leaving her daughter behind. Her father was held hostage until Stockholm Syndrome kicked in, mentally binding him to his captor. Plus, he is now trapped by her and probably has the worst possible opinion of her. With the factors of a crazed uncaring mother and a father resentful towards her mother, Yan-chan probably killed off her emotions a long time ago so she could keep some remnant of sanity after the revelation that she shouldn't even exist. Her crush on Senpai may not only be because of the yandere gene, but because she may have found someone who she believes honestly cares about her.
Actually, she says in the intro that she never felt emotion to begin with, and the Dev has all but outright stated this is typical of Aishi women. She may have sociopathy, which allows you to hold relations with some people. Also to add, her description of "a longing, a yearning, a craving" doesn't mean she believes he cares for her, or that she cares for him, just that she loves the feeling she gets when around him.
Also, the 10th Basement Tape heavily implies that Mr. Aishi does care about Ayano, regardless of how she came into being; if there's any resentment, he doesn't show it in that tape. Ryoba definitely cares about her daughter why wouldn't she? Ayano is a living manifestation of Ryoba's love for her "Darling".
In the 10th Basement Tape, Ryoba describes The Journalist as someone who she hasn't seen in decades, then says, "and by that, I mean he hasn't seen me in decades." It's very likely that Ryoba had followed this man for nearly thirty years, stalking and keeping tabs on his life and whereabouts to take revenge for trying to put her away and keep her from having her Senpai or to make absolutely certain that he would never be a threat to her happiness again.
You can kill Kokona during her Monday morning phone call. Though terrifying in itself, imagine being on the other end, most likely a Dirty Old Man, setting up your next compensated date when all of a sudden there's a scream of surprise, the sound of someone being stabbed, then a weak gurgling before the line goes dead. The girl you were compensating died while talking to you and you have to live with that forever in your memory.
The plot of the April Fool's Dating Sim kicks off when you find the bloody Ritual Knife and then accidentally get transported to the Demon Realm when you put it back. Okay so far. But, if you decide to tell the teacher about it instead, Yan-chan shows up to retrieve it. Oka is both an official rival and the President of the Occult Club. Do the math.
As terrifying as the game's premise is, imagine what happens after a Game Over, particularly ones where Yan-chan is arrested. Think about Oka's reaction when she learns that her new friend who expressed interest in her club and humored her attempts at summoning demons not only was a False Friend, but was probably planning to seriously hurt her. Think of Budo, who would have begun teaching that new club member everything he knows, only to find out that she was a Serial Killer who wanted to use the skills she learned for evil. Think of the Photography Club's reaction when they realize that the quiet girl who goofed off with them is the murderer they've been tracking. Think of how Rino Fuka would feel when she learns one of her students killed another student on campus. Now finally, think of Senpai's reaction when he learns that it all was for him. Needless to say, there's going to be a lot of hurt feelings and trauma once the Awful Truth comes out.
The part with Senpai is heavily implied to be the case in the second part of the Osana update video; Senpai is said to have his own "Sanity Meter" and it will take a hit every time someone close to him either goes missing, dies, or dies right in front of him in ascending order of sanity lost. It's also implied that, if Senpai is on his last bit of sanity, and he finds out Ayano was the one who did it, he might straight-up try to kill you.
Doubles as a Fridge Tearjerker and Harsher in Hindsight, but poor Kokona is engaging in compensated dating and selling panties to boys in desperation to make ends meet with her father's debt. You can take all this information and use it against her, along with everything you can frame her for. You can expel her, murder her, or have her Driven to Suicide. No matter how she's dealt with, what about her father, who's not as bad as we thought? The best case is he doesn't have to pay her tuition fees; the worst case is she ends up dead, and at this point, Kokona very well may be the only thing he's living for.
Kokona also says that she's doing everything she can to help get her dad out of debt, but the only ways to make money fast are "...gross." She may be hinting that she's performed sexual favors during one or more of her compensated dates just so she can get as much money as possible.
Thankfully, it's entirely possible that Kokona was not describing something she herself had to do. Yet. Considering Yandere Dev says that Ayano saved Kokona from having to become a teenaged prostitute by kidnapping Musume, she may have been describing those things to make money fast as "gross" because she knows what she CAN do in order to make more money more quickly, but is incredibly hesitant to actually go through with it.
As part of her routine, Musume gossips with the Rainbow Girls, implying that she's actually close to them. What's worse a prospect: that she and Kokona don't know that Mr. Rokuda is the loan-shark preying on Mr. Harukawa, or that one or both do know?
If Kokona knows or does find out that Musume is related to the loan shark, how long do you think it'll take for her to put two and two together about the fact that Musume's personality change occurred around the same time Yan-chan took care of Mr. Harukawa's debt via means she wouldn't discuss? Add to that the fact that she promised to leave Senpai to this maniac in exchange.
Sure enough, we actually got an answer on what'd happen if Kokona found out about Musume. In one video, Ayano decides to tell her, deliberately emphasizing that Musume is a Spoiled Brat who begs for expensive things bought using money from his victims. She then manipulates Kokona into killing Musume in a fit of rage.
Imagine what would have happened if Kokona's father stayed in debt. How desperate would Kokona get after a while? Would she try anything more extreme than Compensated Dating and selling underwear? And Saki almost sold her underwear to help her despite not knowing the extent of the problem. What would Saki do if she knew that the issue was even worse than she realized, and how desperate Kokona was?
If you don't kidnap and traumatize Musume, Kokona's father will remain in debt. As far as can be seen, the Matchmaking elimination method, while harmless, will not solve the Harukawa family's debt problems. Suddenly, holding Musume ransom sounds like Necessarily Evil to save Kokona's family (and all the debtors of Ronshaku Loans).
The blow of this is softened slightly by the actual Matchmaking elimination method. Kokona's alternate match is Riku, whose family has a significant amount of money and he seems to be the sort of man who's more than willing to help his girlfriend and her family out of a disgusting and traumatizing situation.
This is the personal headcanon of YanDev himself, as seen here.
Even if matchmaking Kokona with Riku does indirectly solve her problem with debt, Ronshaku Loans will still keep extorting other clients unless Yan-chan holds Musume hostage anyway which she has no reason to anymore.
How exactly did Osoro get those horrific scars?
Well, it probably happened in the supposed incident that inspired the bullied to become the delinquents. Genka does say that all versions converge on Osoro standing on unconscious students, heavily bruised and wearing a tattered coat.
In a Twitter post, YandereDev had stated that in the event an Aishi woman's husband passes away before her, she will take her life without a second thought. What if she passes before him? Will their daughter be instructed to orchestrate the murder of her father, then claim he died "of a broken heart"?
As mentioned above, the continuation of the Aishi family line is Serious Business for it. Since a Female Senpai is an option, Ayano could potentially end the line with that. Ryoba might be willing to let this slide because she knows full well that trying to break them up would be a lost cause, but who's to say she can't try for another child and start the cycle over again? For that matter, it's heavily implied (at least two generations back say this) that all of the Yanderes in the line were females. Are the odds really that high that no-one in the line had any sons? What became of them?
However, a female Senpai might not be the end of the Aishi family line, as IVF is an option for lesbian couples. Ayano could still have a baby with her Fempai by impregnating her with her eggs. The Aishi line could still live on
It's been hinted that Yandere-Dev may create a Yandere-kun as a potential reward for hitting a money raising goal that is sufficiently above whatever is set as the goal once it goes into the Kickstart phase. If Yandere-kun makes it into the game, it means that the yandere gene can be expressed in all children with a yandere mother.
Genes are not the only thing that parents pass onto their children. There's also the memes. Yandereism may also be mimetic. Since a Yandere would probably end up "acquiring" a baby in the case that their Senpai was unable to give them one, either from being infertile or not having the right parts needed for babymaking, the baby will probably end up being raised into becoming a Yandere.
With 1980s Mode having come out in October 2021, getting the secret S+ grade in the court trial will show a timeline after the credits that confirm Ryoba has a younger sister, who gave birth to Ayano's cousin the same year Ayano was born. Even if Ayano got a Fempai, her cousin would most likely continue the bloodline with a male Senpai.
More on the fridge horror of Yandere Simulator genetics the fact that Aishi family yanderes don't experience emotions until they meet a certain person implies that there very well may be a "Senpai" gene to go with the yandere gene. This means that a child that doesn't inherit the yandere mindset could wind up with their sibling "imprinting" on them if there is a sufficient age gap or the gene only prevents parent-offspring imprinting.
There is also Mida Rana, the teacher that is the rival of week seven. She uses her job to get access to teenage boys, in order to manipulate them into having sexual relations with her, by using her body, authority, and the vulnerability of her preferred victim demographic. She specifically targets teenage boys, and while the boys at Akademi High School are noted as being eighteen, there isn't an implied minimum age of her victims beyond them being teenagers. In other words, a sexually aggressive woman with what seems like ephebophile tendencies has a job that grants her nearly daily access to potential victims! Her profile also reads as her losing interest in her victims once she manipulates them into having sex with her. And she wants to make Senpai her latest victim!
In an amusing case of Developer's Foresight, Info-chan has a unique response if you somehow manage to take a picture of Nemesis-chan's panties ("How peculiar. I don't recognize these panties"). Info-chan is also able to recognize other girls' panties, even if no other identifying features are in the shot. This implies that she has received so many panty shot photos that she can recognize who wears what underwear just from a quick glance. She really is that prolific. And then there's the updated line.
Okay, so the good news is that it seems Osana's elimination method will NOT have you break into her house. But if that's not her elimination method then whose house is Yan-chan breaking into?!?
Related to the above, the proposed Yakuza elimination becomes worse when you consider that it can be used on Osoro. This is disturbing for two reasons: one, Osoro is a delinquent who's established to be the strongest in the game. She's likely not only aware of her strength, but takes pride in it. Throwing her against something even worse than her gang and then forced into a hopeless situation she just can't fight out of must be particularly traumatic. And two, you gain access to this elimination by helping out one of the delinquents (read: one of her cronies), who then directs you to his Yakuza older brother. Word of God says all of the delinquents look up to Osoro and get their self-worth from her approval. In other words, you're convincing someone to kidnap a woman his younger brother has admired and idolized, then do something unknown-yet-nasty to her. Yikes.
While Kokona being driven to murder Musume is already horrifying enough, things might get even worse in the aftermath. Think about it: how would Mr. Rokuda react to the news that his beloved daughter was killed by the daughter of one of his debtors? Things might go From Bad to Worse for Kokona's father In all honesty, who's to say that whatever consequences that Kokona's father might suffer from his daughter killing Musumemight have been something Ayano intended? Given how royally screwed up Ayano is and how elaborate her plans can get, it's really not a far fetch for her to not only have Kokona arrested for a murder that she orchestrated for Kokona to commit, but to also rub additional salt in the wounds by putting the one person that Kokona loves dearly and was trying to help either in deeper hardship or even dire danger. All for "getting in the way" of Senpai.
Just what sort of deal does the Headmaster have with Mr. Saikou? How and why does it involve Yan-Chan? Well, Mr. Saikou is the father of Megami, the game's final rival. Taking a look at her dialogue from the laptop, Megami knows who and what Yan-chan is, and says that her father won't allow her to attend school while Yan-Chan is active. She also says Yan-Chan is only allowed to exist because she "serves a purpose." The Headmaster is clearly aware that Yan-Chan is dangerous and prepared himself accordingly. Is the deal that Yan-Chan is free to kill off other students so his daughter can be with Senpai?!
So, Ayano is unable to eliminate Osana or sabotage her interactions with Senpai, allowing both for Osana to confess her love to Senpai and for him to reciprocate that love. This is certainly a beautiful ending for Osana and Senpai, except the confession cut scene appears to bear some resemblance to the promo video where Ayano witnesses a successful confession, brutally murders the girl who confessed, murders Senpai, and then proceeds to commit suicide. Even if Ayano is defeated, it does not necessarily guarantee that Osana and Senpai will be safe from her immediate, or future, retaliation. To make it worse, this concept can also apply to any time that Senpai accepts a love confession from anyone who is not Ayano.
Regarding the metal detectors they will spray pepper spray (dont ask) whenever a student passes underneath them holding metal. But what if someone has a phone? Or metal jewellery? It's rather likely this is just a temporary effect of the currently unfinished system. IRL there is usually a tray next to the scanners for people to place innocuous metal items in, which will probably be implemented in the finished system. The pepper spray is just there as a placeholder effect to subdue Yan-chan, and will likely be edited out.
Notice that throughout the "Bullies" video, the Student Council does nothing to stop the bullies. Has this been going on so long that there's nothing they can do? Or is it that they won't do anything?
Potential Fridge Horror for the setting. Yandev has stated that once a Yandere managed to capture their Senpai, they pretty much focus on them to the exclusion of everyone else, family included. Some Yandere might have had multiple children with their Senpai in the past. We know NOTHING about Grandma Aishi or the rest of the Aishi clan. What's to say that Akademi High doesn't end up playing host to Ayano's estranged cousin, also a Yandere AND is focused on Senpai?
If you look at the pictures of the Delinquents prior to idealizing Osoro, one of them (Gaku) has his arm in a cast. This implies the bullying was so severe, they weren't just teased, but outright physically assaulted. No wonder they look up to Osoro.
Just any student with a Spiteful persona full stop. While wanting to see cruel bullies and jerks dead may make sense, depending on the magnitude of said cruelty. Just what kind of a person would display glee at seeing someone they dislike killed; those who had done nothing wrong, those who are decent and likeable, those who only had minor flaws, or harmless quirks those whose only crime is simply EXISTING in this world. The horrifying part? These types of people exist in real life! A sane person will let you know that having this kind of persona is an indicator of a hateful jerk/cynic.
The background details for all three of the current Befriend/Betray missions become this if you're in any way familiar with certain hentai tropes, compounded by both the Theory of Narrative Causality and how Troperiffic the Game's universe is:
Kokona's Mission: A high school girl, whose father's in debt, doing implicitly, increasingly more risqué forms of sex work in order to help pay it off. While, at the point in the story where it's brought up, Kokona has only been going on dates with old salarymen and selling her used panties to boys from other schools, but sooner or later she'd either eventually have to go all the way and actually have sex with somebody or something really bad will happen and Kokona will end up becoming someone's Sex Slave, possibly Mr. Rokuda's.
Osana's Mission: A creepy stalker, obsessed with the protagonist of a Magical Girl Warrior anime, kidnaps the pet of a girl, who looks like the magical girl he's obsessed with, so he can lure her to his house and force her to dress as the magical girl in question. There are a number of hentai involving similar premises, and let's just say that if events play out the way the stalker hopes, Osana will probably end up thinking she's Pretty Miyuki.
1980s Mode Mission: This one's just straight up lifted from the premise of half a dozen hentai: a creepy guy taking pictures of school girls hiding out in a creepy abandoned building. In all likelihood, his end goal was to lure the girls to the asylum using the pictures he's taken as blackmail and, well, you can probably figure out the rest.
Furthermore on 1980s Mode, Getting the S+ Secret Ending shows a timeline that confirms Ryoba has a sister.Who gave birth to Ayano's cousin. Considering the Aishi bloodline starts in 1780, just how many other Aishis gave birth to more than one daughter between then and now? There could be Aishi girls spread all over Japan kidnapping Senpais from every corner
Why does Yan-chan own a vast collection of underwear that ranges from inappropriate to impractical? The Cute Bear Panties for example. Why would any teenager still have those? Even the description asks why they're there. Or the Low-Leg Panties they're described as ready to slip off at any moment. Or the fundoshi, which is traditional Japanese men's underwear. Then there's the Tiny Thong Panties, whose description clearly states that Senpai could never love a girl who wears something like that. But then, Senpai also could never love a murderer, yet Yan-chan kills people like it's going out of style.
Simple, Yan-chan knows she'll eventually end up sleeping with Senpai. But she doesn't know what color/style turns him on yet, so she bought them all just to be safe.
Also, plenty of women enjoy having a wide variety of underwear types, though in Yan-chan's case this is less likely seeing as she's an Emotionless Girl.
YandereDev did mention the idea that the selection of clothes you have at the beginning of the day helps set a person's mindset. The bonus each type of underwear gives is merely from Yandere-chan being in the mindset she chose for the day.
The teacher can expel Ayano if Yan-chan acts insane, is seen with bloody clothes, or is carrying around a weapon. Okay, fair enough. She can also get expelled by standing around in the wrong classroom too long, which is still understandable. But if Yan-chan is caught committing murder or is clearly connected to one, the game says she only gets expelled? What.
It could mean it's the more immediate thing, or perhaps that the teacher says it and Yan-chan zones out afterward, which would explain the black screen.
Blame the process. Later updates have provided more varieties of Game Over. Now, if a teacher or hero pins you for murder, you're "Apprehended". Similarly, if the cops catch you, you're "Arrested".
Also, the school counselor is now in the game. She's currently only partly-functional, but her job is to dole out lesser punishments for minor rule infractions like hanging around in the wrong classroom.
In the game, if a teacher catches you with low sanity, you'll be expelled. If a teacher catches you once you go home (assuming you've completely cleaned up all the evidence and the cops weren't called) they don't do a thing. Odd, especially because Japanese teachers and schools particularly wealthy ones like Akademi do care what their students are doing out of class, and are known to try and micromanage a lot of it.
Dev actually answered this in early 2017. Apparently, Akademi's enrollment has fallen significantly over the past several years partly a victim of its own success and reputation so the Headmaster decided to relax a lot of rules to try to boost the school's population. That's the official reason why students have such crazy hair colors (most Japanese schools strictly ban hair-dyeing).
When holding a suspicious weapon, other students will notice and you'll take a hit to your reputation. Senpai, however, will immediately assume you're going to hurt someone. (You probably are, but still )
The arrows where his attention begins to notice you more would suggest that he notices you being odd around him, regardless of whether you hear him say anything.
The end-of-day text will say that Yan-chan is waiting at the gate for Senpai even if Senpai has gone home already and you've seen it. The same thing happens if a teacher finds a corpse/weapon/bloodstain at the end of the day and "instructs all students to stay" even though everyone has left.
Blame the fact that this is a game still in development. At this point, it's not an Obvious Beta; it's not even alpha (though it's close to that point); it's a pre-alpha sandbox to test mechanics and check for bugs. One would expect things to make more sense once the game has more game to it.
The game is one, according to YandereDev, after all of Yan-chan's rivals have been 'eliminated', since this allows her to confess knowing Senpai won't reject her for anyone else. In theory, this makes sense. But it's more likely that Senpai, after seeing their friends/family turn up murdered, would be suffering from such severe PTSD that he wouldn't be in any state of mind to accept her confession. This is all assuming, though, that a 'Yes' from Senpai really matters to Yandere-chan at that point, or that she won't just go the same route as her mother and kidnap him.
YanDev said Yan-chan will enter into a one-sided relationship with Senpai if his sanity gets too low.
Additionally, there are now non-lethal elimination methods being implemented, and using those without a single fatality will probably lead to a Golden Ending, similar to the True Pacifist ending in Undertale
Even with the pacifist methods, Senpai's not going to be so mentally intact. Let's say that you go with matchmaking and sabotage as the methods Ayano goes with. The fact is that for matchmaking to work, the 5 sabotagable events for each of the rivals still happen and Ayano hasn't interfered with them. Senpai thinks that rhese girls are going to confess to him, only for them to be swept off their feet by someone else. That's going to hurt him in the confidence, probably to the point where Ayano isn't going to need to carry on the Aishi tradition of invoking Stockholm Syndrome to get the love of her Senpai
Some of the planned rivals are the school nurse, a substitute teacher, club presidents, and Senpai's little sister. Most people will assume that, being club presidents, they're going to be seniors, so Senpai can't be their sempai, and he obviously can't be the teacher or nurse's sempai. Imouto-chan has a way around it (she can just call him Big Brother), but the other rivals don't.
Some Japanese schools will have juniors serve as club presidents particularly in the final term of the year because the seniors are too busy prepping for university entrance exams to actually run their clubs. However, this game's story mode runs from April to mid-June (the first term of a Japanese school year), so that's not a great excuse.
Maybe he missed most of the previous year due to illness and got held back, so he's actually older than all the other seniors, and his classmates call him "Senpai" out of habit and/or respect? That would also explain how Ayano-chan doesn't already know him despite Akademi's small student body and her being a junior he wasn't there when she was a freshman. That's still no excuse for the substitute teacher or the nurse, though.
Honestly, depending on how the game's dialogue is written, rivals may not ever have to address him by name or title. Less than half the girls in the Rival Intro Video Amai, Kizana, Asu, and Megami actually call him "Senpai". Osana, who is a year below him, calls him "dummy". Oka and Osoro both call him "that boy". And again, the game is still in development, so very little is set in stone.
In Preview #7, a wood-chipper is shown on campus. Why would it be there? Does the Gardening Club use it for something? And surely something this dangerous would be supervised by an adult to prevent injury
Yan-chan won't confess her love to Senpai until she's eliminated everyone in her way. I can accept that premise. But how on earth does she know when she's eliminated every rival for his affections? She had almost no way of seeing Muja, Mida, and Hanako being obstacles, and it's not like Oka, Osoro, or Megami are likely picks to fall for Senpai. How does she know 'All right, Megami Saikou is the last rival, I can claim Senpai now.'?
Maybe she starts off every week planning to confess to Senpai, only for her focus to shift on eliminating the rival once Info-chan tells her about them. Perhaps after some time has passed without an update from Info-chan, she'll make her move?
This is the case at least for Amai, the second rival. She finds him feeling down for Osana either not confessing (due to matchmaking, Betray/Befriend, etc.) or not being alive, and offers him some baked treats to try and lift his spirits Then the camera pans back during the last few seconds to show Info-chan recording it from a distance and sending it to Ayano. So its likely that either she or Ayano herself will find similar scenes in the following weeks.
How is the 'expulsion' elimination method going to work for Muja Kina and Mida Rana? They're faculty, not students. It's not like you can report a teacher to the guidance counselor, nor would a nurse plausibly want to steal test answers.
Likely a special variant, like showing evidence they had been messing with Senpai or other students.
Since they're adults, the "Expulsion" method in their cases could perhaps be more appropriately referred to as the "Firing" method where you need to plant or give evidence for them to be fired from the school. Mida Rana might actually be easy in this regard if you can dig up her old "History", whereas Muja Kina might need to be shown (or "shown") how her clumsiness can cause major accidents.
In the basement tapes of Jokichi, he actually did recognize Ryoba by name as he was kidnapped. However, it's unclear if he remembers her face and name because she was at school or because of the trial. If it is because of the trial, then it's a huge case of Artistic License Law, since any serious crimes involving minors in Japan have said minor's name censored and deliberately hide their appearance, so she would've been referred to in the media coverage of the trial as Girl A.
In 1980s mode, Ryoba's narration states that the news of her murder trial spread accross the entire nation and that "everyone knows [her] face and name".