Katawa Shoujo/Fridge

Emi

 * If you make the wrong choice in Emi's route near the end,
 * Actually,
 * Near the end of Emi's path, you find out why she tries so hard at keeping people at arm's length. In the end, it makes the fact that their relationship succeeds all the sweeter.

Hanako

 * When you first meet her in the library, you discover that she's reading Life of Pi. Considering the plot of the book centers around a boy who lost both of his parents in a tragic accident and is stuck in the middle of the ocean (almost) alone with no other person to relate to, and you can see why Hanako seems to have taken such a liking to the book.
 * The final CG's in "Misstep", Hanako's explosive and traumatic bad end, is the one place in the game where her face isn't obscured by anything. Her physical form mirrors the fact that emotionally, she no longer hides anything.
 * Similarly, in her Good Ending,.
 * Furthermore,
 * Hanako's Neutral Ending
 * Hanako's path deconstructs White Knighting, and as a result, requires Hisao to open up to Hanako and bare his weaknesses to her as well. He can't help her as a superior; it has to be as a peer, and he has to be asking for help as well. The two need to develop a mutual trust. This is most evident in Hanako's H-scene, where they're both at their most vulnerable and consequently, requires the greatest level of trust: Hanako because the entirety of her scars are on display, and Hisao because the action places stress on his weakened heart.
 * Hanako's room being bare and devoid of decorations is interesting in two regards. Firstly, it strongly resembles Hisao's room, and as he points out, his view of his condition, including lingering depression and the belief that it defines him, is Not So Different from hers. She also most likely had a similar experience in moving around between rooms, going from her own room to the hospital, then the orphanage, and now to Yamaku. Secondly, her Only Friend at the start of the game and the only person besides Hisao to set foot in her room is blind.

Lilly

 * In Lilly's route, Hisao passes off her sudden enjoyment of wine as a vice, similar to her tea addiction. Initially, this judgement this makes sense considering, but then Fridge Brilliance kicks in. Anyone who's ever tried to taste wine properly knows that there are a multitude of factors involved in judging a wine, most of which are not related to it's appearance. Things like smell, texture, body, acidity, variety of grape, aftertaste, flavours etc. To Hisao, or most people for that matter, these would be an afterthought since it's just booze to him. To Lilly, these things would immediately stick out to her since her other senses are so much more sensitive. Even the sound of the wine sloshing about in the glass would be something new and exciting to Lilly, so it's no surprise she takes such a fast liking to it.
 * Exactly why does Hisao's heart act up more on Lilly's route than on any other route? It's because he's been drinking both more tea and alcohol! There's no way that increased consumption of both a type of depressant and a type of stimulant can be good for his irregular heartbeat.
 * Doesn't help that he keeps forgetting his medicine on that route either.
 * Both coffee and alcohol have an effect on heart rate. He's also far more active in short bursts but no has gradual exercise in that route.
 * He tells the nurse that he's been getting some exercise when seeing him after the incident at the Satou family summer house, although we rarely see much of his exercises in the routes besides Emi's.
 * Lilly's route is the most delicate of the five; it's quite possible to This reflects her desire for a perfect fairytale-type romance, and her tendency to act calm and composed all the time, rarely talking about her own problems even when something is seriously wrong.

Rin

 * One of the key choices that players seem to get stuck on comes at the end of her route.
 * I had no drinks in my mouth to spit, but let it be known that if I had some, it'd be your fault. You just enlightened me.
 * Rin's route has probably the most But Thou Must! in it, despite having the most choices.
 * It's hard to call such a... potentially squicky fact brilliant, but it's there nonetheless:
 * It's also sort of symbolic in that
 * One of Rin's famously funny lines is "Underpants are the soul of a girl. You shouldn't peek at someone else's soul." There are exactly two scenes where we see Rin's underpants, and they both happen around the time of Rin revealing something important, intentionally or not. She's showing Hisao her soul.
 * Rin doesn't title any of her works so that people aren't influenced by anything but the work itself,
 * Rin doesn't title any of her works so that people aren't influenced by anything but the work itself,

Shizune

 * Fridge Brilliance makes Shizune's route more enjoyable on subsequent playthroughs.
 * Deaf-mute people have a tendency to be particularly blunt and direct when expressing emotions, stemming from the necessity of being understood in ways different from the talking. Suddenly, parts of Shizune's personality start having more sense - at some points, it's even stated outright that the communication problems stemming from her disability are a source of frustration for her. A22 (The main writer for Shizune's route) very much deserves credit for not simply making her a straight up Tsundere, which arguably would have made her less of a Base Breaker, in order to portray this as realistically as possible.
 * During the playthrough it may seem like her story is, but then, near the end, Hisao comes to the realization that.
 * Shizune's first H scene has an odd fixation with hands:

Meta

 * All of the girls' routes have an important message on how have to healthy relationship. Shizune's is obvious: . In Lilly's route, . With Rin, . Hanako makes it clear that . But Emi's route also lets you know that.
 * The way in which you must make your choices to reach each character's route in part reflects their own personality. Shizune, . As Lilly   Hanako   Emi,   Rin,   Viewing a flowchart of possible Act 1 choices make these relationships a bit more obvious.
 * Harem or Threesome ends are impossible. Even if their were a way to make it in character, Hisao's heart condition makes it so that even regular sex carries a risk. How's he going to survive the stress of trying to juggle multiple relationships, even if it weren't out of character for those involved?
 * Typical male fantasy sex is also out:.
 * For all the flack that Shizune's route
 * Additionally,
 * The development team's imageboard is called the "Mishimmie" and all guests who post comments on the art there are listed under the name Shiina "Misha" Mikado. Having an entire imageboard filled with Misha's drooling over pics of the various females becomes particularly funny when you go through Shizune's route and learn that.

Fridge Horror
"Meiko: Rin's art is one of those things that I don't think I'll ever understand.
 * In Hanako's route, when she, she notes: " "
 * Not only that, but
 * And God only knows how long it took for the fire department to come.
 * Even more horrifying, though is that  . Instead, it was
 * Think about it. How horrifying would it be if you can hear one of your friends in distress, but you can't see them, have no way of finding them, and don't know how serious the problem is? Congratulations, you now know what Lilly was feeling when
 * The friend.
 * And how could it be worse? It happens again, only this time
 * Every heroine in the cast has their own set of personal issues. While some may not cause problems if they aren't in a relationship with the main character, others have issues that could very well lead them to a horrible fate regardless of whether or not Hisao comes into their lives. What happens to them without Hisao's interference? Perhaps it's best that we don't find out. That, or if we don't see it, it doesn't happen.
 * Of course, Hisao has his own influence on them that, in some ways makes them worse (but to an extent, forces them to confront said issues).
 * Hanako's complexes become worse due to Hisao's White Knighting, whereas in Lilly's path, she opens up somewhat more easily and makes friends besides him and Lilly.
 * Rin is hesitant about the art exhibit, (and in Emi's path, is slightly annoyed by Nomiya's telling her to work harder), until Hisao convinces her to go for it.
 * Misha's pain over Shizune's rejection is exacerbated by Hisao getting closer to Shizune. Then again, their impending graduation also plays a part, and Shizune's route is the only one that goes past summer vacation.
 * Fridge Horror abounds in Rin's route.
 * Let's not forget her second Bad Ending.
 * Also largely ignored is
 * Another little bit of Fridge Horror for Rin's path. When Hisao finds her in the atelier, she asks if he's her friend, and he agrees but also lets her know what she wants from him is not something friends do. Her response is simply to ask if they can't be friends anymore. You find out on Emi's path that Rin does not feel the need to change the term friend to boyfriend or girlfriend. Hisao, in Rin's mind, pretty much said that if they had sex, they would have to break up. (It's not like that in his case, but she's no mind reader.)
 * In Shizune's route, you learn that Misha frequently skips classes after overeating, an act that she keeps doing despite her knowing her limits.
 * Also, worth noting is that overeating is often
 * During a dialogue with Hisao, Misha
 * In Emi's path, the following exchange takes place:
 * In Emi's path, the following exchange takes place:

Emi: That's not surprising. I don't think Rin expects to be understood.

It sounds okay on its own, but if you know what happens in Rin's route, Harsher in Hindsight hits you like a sledgehammer."

Fridge Logic
"Lilly: There are ways around it. Some meals are more difficult to cook than others because of being unable to see what I'm doing, but it usually only takes a little more time. Fingers can double as very useful measuring tools, for example.
 * How bad of a cook must Akira be, if her blind younger sister did most of the cooking?
 * A lot of cooking doesn't really require sight. Most of the ingredients are measured out somehow, and temperature and smell are really important to see if a dish is done.
 * So you're saying that Lilly stuck her finger in the hot food to see if it's ready?
 * Or, you know, held her hand seven or eight centimeters above the pot to feel the heat rising off a given pot (or opened the oven to do the same in the event of baked goods).
 * Of course, she could have had Akira check things like that, and still done most of the work herself.
 * Also, some of the more important requirements to be a good cook is to have a good sense of timing and taste.
 * However, Lilly does admit that some dishes are naturally harder to cook than others when blind.
 * Except it's heavily implied that Akira simply doesn't have the time to cook, since she has a fairly busy executive position.
 * Lilly makes a remark on her methods and the associated difficulties in her route.

Hisao Narrating: It makes sense, but she'd have to be pretty careful not to hurt herself. I wonder how many times that's happened, since she's cooked alone for possibly years while Akira worked and her parents were gone."

"Lilly: ("Pseudo Tea Cosy") I'm in class 3-2, which is on the third floor, same as yours. It's taught by Miyagi, and is specifically for blind and partially blind students.
 * Rin wears the male uniform. And she wears a tie. Which shouldn't be possible because, you know, she doesn't has any arms! I know that she uses her feet to accomplish things other people use with their hands, but this is just ridiculous!
 * It could be a clip-on. And if you've seen any documentaries about real people who can't use either arm for various reasons, and the dexterity they develop in their legs/feet, it's not very far-fetched. A tie knot isn't that complex, and Rin could probably even crochet if she wanted to.
 * It's implied that Rin can dress by herself, although with some dificulties. It's even implied in one scene that she can put on a bra on her own - not a sports bra or anything, mind you, but a clasical bra, with a clip on the back. If she can do that, nothing else is really surprising.
 * Eh... it's stated in the game that Emi helps her get dressed every morning.
 * Related: she wears a male uniform because, as she needs to use her feet for tests of dexterity, wearing a skirt would mean nigh perpetual panty shots.
 * Which raises an entirely different question, given Rin's casual relationship with reality: Did she actually notice and/or care, or did someone else have to convince her that it'd be a better idea if she avoided skirts.
 * She does seem to care as she believes that "Underpants are a girl's soul. You shouldn't peek at someone else's soul. Even if you are not a girl."
 * She would run into the same problems with the girls' uniform, which also has a button-down shirt and a ribbon (virtually every time a male uniform includes a necktie, the female uniform has something for the neck, sometimes an actual necktie).
 * Misha and Shizune are the whole student council. There were fewer members last year, before Misha came in to help. So Shizune was running the student council alone.
 * Not quite. Lilly was originally part of the student council, before the Noodle Incident happened.
 * Lilly and Shizune were both in the Student Council for a while. Noodle Incident happened, Lilly left. Maybe Misha didn't start until a year after that. OP's reasoning is still sound.
 * From the photo shown by Akira (towards the end of the Lilly route), Misha was around and helping out Lilly and Shizune before the Noodle Incident, making it likely that the three were working together first. (Although that incident did involve noodles).
 * Lilly's recollection of earlier times (during Shizune's bad ending route) is that the student council used to consist of more people, not just Shizune, Lilly and Misha, but also other students. Those people all got tired of Shizune's extremely ambitious attitude and Lilly's attempts to slow things down just caused fights. Lilly was the last one to jump ship.
 * Here's an approximate timeline
 * 1) Shizune joins.
 * 2) People start leaving.
 * 3) Lilly joins. There may have been people still on the council at this point.
 * 4) Misha joins when only Shizune and Lilly are left; she says they were the only others when she tells about her past.
 * 5) Shizune and Lilly have their falling out, and Lilly leaves.
 * Regarding the Satous' visit to the Hakamichis' house in Shizune's route, Hideaki mentions that their fathers are brothers. So why do they have different last names? Did one of them (presumably Shizune and Hideaki's father, since the Satous are only half-Japanese) take on their wife's name upon marriage?
 * Given the fact that Lilly and Shinzune's fathers hate each other, this is probably the case.
 * Actually, the devs clarified that Shizune and Lilly's fathers are brothers in law, not blood brothers. Lilly's aunt married Jigoro.
 * Hisao probably wouldn't make as much of a fuss about taking his pills if he realised that one of the common medications prescribed for cardiac arrhythmia and similar diseases is Sildenafil. More commonly known as Viagra. Explains a bit about his extracurricular activities.
 * Some of his other pills have erectile dysfunction as a side effect so it probably just balances out
 * Doesn't Lilly ever get pissed about nobody in Japan being able to pronounce her name? I believe people who's native tongue is Japanese would have a hard time making the "L" sound.
 * As stated by Kenji, there's much surprise when he realizes Hisao and her have been on first name terms. It's much probable that, be it due to social norms or practicality, she's only ever called by her surname.
 * Oddly enough, he calls her "Lilly" during one scene with her late in her route, and she once refers to him by his first name.
 * It would've make sense if Hisao just got a pacemaker installed, he could've just gone back to his old life instead of Yamaku, or gone to Yamaku and not worry about taking a cocktail of 17 pills a day. The medical staff would just make adjustments to the Pacemaker or check on it if the need were to arise.
 * My uneducated guess is that Arrhythmia causes the heart to fluctuate in its heartbeat rhythm. Because of the random nature of the electric cardiovascular impulses, adjustments would have been required constantly, which would have made the use of a peacemaker much more intrusive than it should have been. Either that, or they deemed him too young for that kind of treatment.
 * Pacemaker intrudes on every single heart beat; large fraction of them actually initiate heart beats. It's hard to get more intrusive than that. You're probably thinking of ICD, implantable cardioverter-defibrillator, which works only when needed and makes much more sense assuming Hisao has Long QT syndrome. But ICD is not a pacemaker, and natural fluctuations of the rhythm shouldn't trigger it.
 * Hisao's condition seems to be much more severe than a "simple" arrhythmia or something like the long QT syndrome. Ventricular escape rhythm (technically a form of arrhythmia, btw) shown during the intro, and an open heart surgery implied in Hanako's route make me think he had some kind of catastrophe in or around the heart, maybe an infarction, and his persisting "arrhythmia" is either a remote consequence, or just the way his doctor explained his state to him. This could explain the pills (well, kind of), a school for disabled and his lack of stamina, but probably not his attacks.
 * Also it could just be that Hisao's parents just didn't want to take the responsibility, and just dropped him off at the school so the staff there could do all the work.
 * In Lilly's good ending, Hisao gets a temporary pacemaker installed, but he's told that within days it will be removed.
 * Hisao could've just called Lilly's cell to ask her to wait up for a minute.
 * The guy was panicking. And for all we know, Lilly's phone may have been off. Plus, where's the fun in that?
 * You have to turn off your cell phone before a plane takes off, and he had no way of knowing where in the airport she was or whether she had turned it off in advance.
 * He probably just thought a phone call wouldn't have been enough to get her to stay, and didn't really think beyond that. Or she turned her phone off to keep him from calling to vent his angst. It's even possible he doesn't have her cell number; I don't recall him ever calling it (the long-distance calls were to a landline).
 * Also, in a crowded and noisy place like an airport, there's no guarantee that Lilly would even notice that her phone was ringing.
 * So, there's this bit in Emi's route where Hisao can't sleep, and he ends up wandering out to the track and falling asleep on the bleachers. Later, Emi wakes him up and they run around the track for a while. Is Hisao jogging...in his pajamas? His school uniform maybe? He doesn't seem to put his gym clothes on at any point, and no one mentions him looking like a doofus running around in pajamas.
 * Since Hisao has to set an alarm to go running with Emi, it's possible they're out at the track before most of the school wakes up.
 * How does Rin open or lock/unlock doors? The twisting motion would most likely require more dexterity than she could manage with her feet.
 * A place built for disabled people usually has door handles instead of door knobs.
 * And, speaking from experience, even a non-disabled person can open doors with their feet.
 * It's possible that if all else failed, she could use her mouth. Not the best idea, for germ-related reason, but Rin doesn't seem like the kind of person that would occur to.
 * Why does class 3-2, the class for blind students, have a chalkboard?
 * The class is for students with visual impairments; Lilly is completely blind, but Kenji has limited vision. There are likely some students who could see what's on the board. Another possibility is that it's standard for the room design, or that it's used for other purposes by students who could use the blackboard.

Lilly: ("Paint by Numbers") Our class doesn't have many students with even partial eyesight, so they're in high demand."


 * Since Mutou is both Hisao's homeroom and science teacher, and Hisao is implied to have a different teacher for English, it's perfectly plausible that Miyagi is Lilly's homeroom teacher, and teaches a specific subject for non-blind students as well (probably geography or history, judging by the world map in the background).