I highly doubt Akira has Hinamizawa Syndrome. He’s not from/never been to Hinamizawa. I feel like that would have come up at some point in the arc if he had any sort of connection with Hinamizawa’s residents outside of Natsumi. I just chalk this one up to good old paranoia and nothing else. That said, who knows? Maybe he contracted it from Natsumi somehow?
Hinamizawa Syndrome is very confusing as a disease. Most germs are essentially spread in one of four ways. Way one is through the air (sneezing, coughing, this is how influenza spreads). The second is through skin contact (this is how you get chicken pox). The third method is by fecal matter that later ends up in the mouth (this is how you get salmonella) The fourth and final is through bodily fluids (this is how you get most STDs/STIs). I’ve always assumed that Hinamizawa Syndrome works through the first method. But looking back at Himatsubushi, I was kinda confused as to why Akasaka never came in contact with the disease. I thought to myself, “maybe you have to live in the village sometime before coming in contact with Hinamizawa Syndrome, instead of just visiting it?” Airborne diseases affect people almost instantaneously, since you just have to breathe in order to come in contact with them (that said, just because you have come in contact with a disease doesn’t mean you always become sick, as sometimes the body will destroy a virus before you even begin to have symptoms).
So, how exactly would it spread to Akira? I think in his case it almost has to be airborne. Due to living in the city, he wouldn’t have to worry about food/water being contaminated with fecal matter. I also highly doubt he and Natsumi ever kissed considering how paranoid the two of them were (so no fluid contact). They could have held hands or something, but one of them would probably have to have a rash (skin born diseases usually take the form of rashes/bumps/distinct skin markings). There are no rashes mentioned here, or anywhere else in Higurashi, so I kinda doubt that Hinamizawa Syndrome spreads through skin contact… But if it spread through the air, then maybe he could have gotten it from his time with Natsumi?
Who knows~ I’m not a med student so I’m not exactly sure how that would work. I may also be completely wrong about diseases in general. As I said, I have absolutely no medical training whatsoever. Those who are in medical school, please correct me as I’m probably wrong. All of this information I’ve gotten either through the internet or my lackluster health education.
But yeah, I agree with you that the whole demon voice thing was rather silly, as well as unnecessary. It’d be a bit more justified if he did have HS somehow, but it’s still a bit too silly to take seriously.
Also, @Seraphitic I completely 120% agree with you that Natsumi feels a little bit too much like a discount Keiichi. I think that’s because like Onikakushi, one of the main themes of Someutsushi is that you should trust your friends. And just like in Onikakushi, a lot of the problems in the arc could have been solved if the friends stopped keeping secrets from one another. I’d like to think this parallel was done on purpose so that new readers can pick up on the similarities between Natsumi and Keiichi so that they can try to solve the mystery of what is happening to these characters.