Note the melon bread.
虫刺され, mushisasare, is being stung/bitten by bugs, so there’s that extra bit of info in the title.
Politeness is a big deal in Japan, and few places is this so apparent as the service industry. Walk into basically any store and you’re bound to hear an “irasshaimase!”, a combination of the respectful verb for “to go/come/be(it’s very versatile)” (irassharu) and a doubly polite way saying please/making a request (-mase). It’s ritualized to the point of almost absurdity in some cases; you’ll hear it not just when you come in, but every time an employee walks by (in say a grocery store or clothing store).
However, in less formal types of stores, like a ramen shop or the neighborhood vegetable store, people will sometimes use it without the -mase and/or with a hai in front. Commonly, with a somewhat slurred/looser pronunciation (hai, irasshai → hei rasshai)—which is what Gab does here.
Basically all that goes to say that here:
He actually says “is she a (vegetable) grocer…?” referring to people like this:
As you can probably tell, she starts speaking in an accent here. It’s not a specific language’s accent or anything, it’s generic “katakoto,” the equivalent of broken English. It’s the go-to way of portraying “foreigner-speak.”
Except then she drops a pretty obscure Japanese proverb, that not even shopkeep man seems to have recognized (the joke of course being “lol she actually speaks the language super fluently”). The proverb is about how it takes a long time and a lot of effort to acquire proficiency in something. Specifically, it refers to being able to properly use the rudder (3 years) and the oar (8 years) on small old-school Japanese fishing boats like this:
You may have seen these terms, tsukkomi (straight man) and boke (dunce), come up in other shows before. The terms come from a traditional (and still widely practiced, it’s a common form of stand-up) style of comedy. It’s basically a rapid dialogue between two performers, one who constantly says dumb stuff (the boke) and one who interjects, in a hopefully hilarious fashion, to correct them (the tsukkomi). It’s especially associated with a Kansai accent for various reasons, though that’s a more modern convention.
The tsukkomi and boke dynamic forms the basis of a huge amount of Japanese comedy, and comes up fairly frequently in day to day life. Characters in media are often defined to some degree by whether they are a tsukkomi or a boke; it’s one of those “there are two kinds of people…” sort of distinctions.
Japanese subs for Hollywood movies are infamously bad. It’s especially mind-boggling when you consider most movies tend to come out in Japan several months after the rest of the world gets them. Ironically dubs tend to be a lot better.
These horror shows, where they basically tell ghost stories and examine “ghost photos,” are pretty common on Japanese TV, especially in the summer. There’s a general idea in the culture that horror is a good genre for hot weather, because it makes you feel colder (sends “chills” down your spine, etc.).
It’s sort of common at certain types of restaurants in Japan (particularly drinking establishments aimed at groups, like izakaya) to offer this sort of thing, “Russian Roulette” food. It’s a popular-ish thing to order as a group, often as part of a drinking game. Another thing people will do is play a game where everyone has to try to guess who got the spicy one.
Takoyaki and cream puffs are two common vehicles for it, since they have a filling you can’t usually see.
The アメリキャンコーヒー (lit. “American Coffee”) is actually not referring to an Americano, that’s a different thing. “American” is the word in Japan for a style of coffee that’s thin/weak and lightly roasted, like American coffee (cue rage). This comes from how European coffee was represented by stuff like espressos, which are pretty strong, while American coffee was represented by “cup of joe” style stuff you can drink several cups of without having a heart attack. The terminology originated in the 60s, back before Starbucks was a thing and dinosaurs walked the earth.
The other options you can see there are seen as pretty high quality (“Blue Mountain”, from Jamaica, for instance has a protected name along the lines of Champagne for wine).
Here’s another example of the service industry politeness thing. In the Japanese she doesn’t say “drink it and get out,” it’s more just like “here, I brought it for you” using a grammar form that implies it was something Stan should be thankful for. Stan’s reaction is “hey use keigo (polite/respectful language) with me, I’m a customer!”
The translation does a fine job of conveying the idea here, I just wanted to bring it up as an example that ties into the earlier point.
You may have noticed that there are constant god/hell/devil/etc. idioms and puns and such in the subs for this show. I just want to point out that almost literally all of them are added by the translator(/editor?), there is basically none of that in the Japanese (i.e. it’s not a Squid Girl situation where they’re trying to deal with her squid puns/”-degeso” or anything). It’s a good example of how a translation can potentially improve the experience imo. Conversational English is steeped in Abrahamic theological terminology, something Japanese lacks almost entirely, so it’s neat to see they’re taking advantage.
“Stepped on a mine” is a common idiom in Japanese for “brought up a subject/said something that caused somebody (emotional) pain,” usually by stabbing at some trauma or insecurity of theirs.
Central heating/cooling is not really a thing in Japanese homes/apartments; you’re generally going to be using a wall mounted unit like seen here, controlled by a remote like this. This usually means only certain areas of the house(/apartment) are kept warm/cool, and that you’d better keep the doors to those rooms shut tight to keep the heat out/in.
Her shirt says “Karuizawa,” a place that’s a short ways outside Tokyo and famous as vacation spot, where lots of rich people keep vacation homes. The shirt design is also pretty reminiscent of the “you work you lose” NEET shirt.
Japan has a similar thing to how in the US (and other places?) Jehova’s Witnesses will knock on doors to try and get you to join their religion. It’s often even Christians (which is a very small minority religion in Japan), though sometimes it’s weird cults. Sometimes you’ll see proselytizers on the street/outside train stations trying to get people as well. Oddly(?), they seem to especially aim for people who are obviously not Japanese, I guess because they figure they’ll be more receptive to a Western religion than the average Japanese person? Or maybe it’s just because they stand out in a crowd. Or maybe because they’re excited to use their English skills.
I’m not sure what “dumb Dora” is shooting for, but the Japanese is just “bakatare,” which isn’t particularly strange or archaic, though perhaps a little more associated with older men and not so much high school girls. It’s mostly just a different/stronger form of “baka”—aho→ahotare is a similar thing. It’s more common in some areas of the country than others (not so popular in Kansai I think?), but it’s not a dialect phrase like gojappe or something.