On the flipside, something most developed countries consider normal but would blow Japanese minds is the ability to do all "paperwork" on your phone or laptop without any paper ever being printed anywhere. Japan is somehow still a country of fax.
i do not understand american's aversion to the bidet. why would i want to wipe my ass with dry fucking paper rather than water? why why why. like it's somehow 'gross' to use water. but scraping at wet shit with fucking tissue paper is hygienic and normal?
They have a device which progressively shines a light on a piece of paper while moving across the page and converts the brightness of the reflected light into an audio signal. Once it reaches the edge the paper is incremented and the process repeats. Each of these segments of sound are sent via a standard telephone connection to a similar device on the other end which uses the sounds to reproduce the image on the original paper on a new sheet of paper. This can be used to send forms, letters, black and white pictures, and even chain letters. It also forms the basic underpinning of a significant fraction of formal communications with landlords, employers, medical systems, government offices, and so on.
Japan's current fiber-optic commercial internet connections use optical fiber transmission windows known as L and C multi-core fiber (MCF) bands to transport data long distances at record speeds. Meanwhile we (USA) have fiber back to copper and Cat3 for the last few hundred feet in most cities at best making the entire idea into a bottle neck.
If you have a large suitcase or other parcel it may be unwieldy to walk around Tokyo or another city with it. Subways only allow one suitcase of a certain size, so you might have to take a much more expensive taxi.
Instead you can go to a desk at the airport and have your luggage delivered same day or next day to ~any hotel, subway station, or convenience store. It will be insured and kept safe for you there to pick up. And at the end of your trip, you can send it back. The price for this convenience? Around $10.
This is not only a good demonstration of Japanese trust and customer service, it's also a legitimately hard logistics problem. I daresay that such a business could not succeed in the US both because of our defensiveness and sprawling cities.
Automatic opening doors but they don't open by a proximity sensor, they open when you press the button. This is the optimal solution as the door doesn't open needlessly but still allows for ease of access.
Ordering machines, where all your menu options are clearly listed and priced. Pressing on a combo of buttons will print a receipt which you can sit down and show the staff/cook your order.
Water (hot and cold) tapped straight to your dining table for self serve drinks.
Unfortunately becoming less applicable with the smartphone domination finally reaching Japan, but their flip phone technology.
Refrigerators that make way less noise than the ones we have here. Japanese more often live in small apartments so noise is a bigger nuisance. But, those refrigerators are ridiuclously expensive by our standards. I had been interested in buying one, oh well.
Can't believe noone has mentioned the hot beverage vending machines.
Its so fucking nice to spend $1-$1.50 and just get some hot tea or coffee right there without issue. And they're everywhere so you can pretty much rely on them.
So much more convenient than having to go to a coffee shop so you can pay $5 for the same thing, and the vending machine version still tastes great.
Japan currently doesn't have this in the more normal sense. That Japan is still super high-tech is more of a PR move. I literally had to send a fax to get my current internet (though it is fiber-to-the-home).
Where Japan is innovating is in robots and also its crossovers with an aging population. Possibly also some space stuff.
But for an everyday person, I don't really see anything that doesn't already exist somewhere else. I was raised in the US and have been living in Japan most of the last 10 years.
From what I see joked about in tv and film: toilets.
From what I know from people who have actually been there personally: Vending machines.
Also they have the most advanced KitKat flavors in the world. I want them. But they're like specialities of specific regions kinda like Pokemon. It's wild.
One that I haven't seen mentioned ever was neat flashlights in every hotel room I stayed in. They were all mounted to the wall, and had no power switch. The wall mount had a tab sticking out that separated the batteries, so when you went to use it, the batteries touch and make the circuit. They were always low power, so that you didn't disturb others in the room, and you have to keep it in its location to turn it back off. They worked well for going to the bathroom at night and not messing up night vision too. I tried finding one in the US, to no avail, but they're all over in Japanese 100 yen stores. A clever, cheap design.
Found at 7-11, combo ketchup/mustard blister pack that when you simply bend and squeeze together, ketchup and mustard come out evenly for your corn-dog and no mess for your fingers.
Bathroom mirrors that don't steam up after taking a shower.
Vending machines that are competent at accepting cash. Everywhere else that I've been to, you have to smoothen the bill and make sure it has no wrinkles or bended corners, and even then the machine would sometimes give you a hard time. In Japan, you just insert a stack (!) of bills, and the machine will count them within seconds, and also give you change in bills, and not a gazillion of coins.
Gates at the train stations are also better than everywhere else. You don't have to wait for the person in front of you to pass the gate, you just insert your ticket and go. You also don't need to look for arrows or notches or whatever on the ticket to insert it correctly.
Electric kettles that are very quiet and keep the water hot for a very long time.
Trains where all seats face the front, so you don't have to sit against the direction of travel.
Not overly high tech but such a good fit for the culture and extremely convenient:
Self-filling, self-warming baths
Put the plug in during the day, press the button to fill the bath at the remote keypad in the kitchen. Baths fills and a little jingle announces that the bath is ready at the perfect temperature.
Not Japan specifically, but I've got say I'm jealous as hell about the snack scene in east Asia.
I generally don't have a sweet tooth, and things like potato chips don't have that umami I like. I try to keep snacks around because I forget to eat, but nothing appeals to me. But man... all those pre-packaged tofu squares, various bits of marinated meat... that's my deal. There's one solid "Asian Mart" near me, I'll stock up a few months worth at a time.
Closest you get in the US is basically jerky/slim jims, which are great but expensive and kind of one note for flavor.
It's kind of a relic of the past now since everyone uses a streaming service of some kind now but right at the end of physical media's lifespan, Japan had some key advantages over the US specifically because it was legal to rent albums and I believe individual songs, just like a Blockbuster. Eventually they had the music purchasing equivalent of Redbox in the form of kiosks as well with the advent of recordable Net-MD minidiscs, which only really ever saw success in Japan.