There is a theory that a very specific smile is Paredolia's, and it's not chapter 4 exclusive. I'm not sure how comfortable I am identifying it until I reach current update, but the picture is from much earlier in the game.
Another text extraction, and I even verified it by guessing the same font, aligning the text as best I could, finding out the correct font size in the process [Arial, 45], and then guessing the missing words until things lined up. (for a while I thought her love for all minds was her love for almonds). I even made an effort to try and be pixel perfect to offset how I don't have the exact text antialiasing settings Sel used (Betting he uses photoshop)
Since I'm attaching all the layers I worked with and even the paint.net project if you want to play with the layers easily, I'm not going to try format the post with several images. Check the "Image with text removed" to remember what image this is.
I am russian and I can confirm that this is accurate. 9th of May is a very big deal in Russia and is celebrated in a bigger manner than any other holiday, except New Years.
I doubt this has anything to do with Chika though, would've made more sense to make a Slavic girl (which we dont have) and give her this birthday, OR give 9th of May to Yumi because she's the favorite girl for most Russians.
Just to throw this out there, (No actual spoilers for where you are) Ami treated Sensei the way he taught her to. She's already seen him at his worst before, knows he wants to be left alone when he's unwell:
(She was apparently taught to milk him, and help him shit in a bucket)
On the other hand, Sensei's too much of a narcissist to actually take care of someone. He just treated her the way he'd want to be treated, except badly. Like Ami pointed out, she'd never expect him to be able to take care of her anyway:
(She's been marinating in her own issues while taking care of Sensei for around 8 years, hence her snapping. (Ignoring the trauma that the resets have also likely had on her))
Basically, they have a fucked up/"special" relationship where Ami acts more like an adult than he does, and that's not good for either of them, and almost no one besides kind of Maya and Niki understand Sensei's and Ami's relationship (ignoring the optional sex). Hence why both Ami and Sensei noted that others "don't get it":
Wonder why Tsukasa calls her sister "nee-sama" when that means big brother while "nee-chan" means big sister. It is something to do with power? Choosing a more masculine nickname because men are stereotypically more powerful?
Also, 'nee' is short for 'onee' which means elder sister, whilst 'onii' or 'nii' means elder brother... Void is probably making this mistake due to western pronunciation norms, 'onee/nee' sounds like 'neh' as in 'eh?', not 'nii', as in your 'knee', that's how 'onii/nii' sounds.
