1. Sushi is all raw
Not true. It may make a better story to tell people that you ate raw octopus, but octopus is routinely poached. Shrimp is also cooked—if it wasn't cooked, it would be gray, not pink. (Oh, and while we're on the subject, those fancy rolls covred with lava sauce or whatever aren't Japanese. They're American.)
2. Geishas are prostitues
The word "geisha" means "arts person," and that's what they are. They're trained in musical instruments, dance, that sort of thing. They may stroke your ego but that's all they're going to stroke.
3. Green tea can be sweet
Oh my God, no. It also doesn't have jasmine in it, or camomile, or whatever. It's bitter and it's good for you, so drink it.
4. Sumo wrestlers wear a "diaper-like" loincloth
I understand that it makes a handy metaphor to describe the mawashi as like a diaper but it's infantilizing, and is often followed by phrases like "giant babies." Yes, Japanese people can kick your ass. Get over it.
5. Panko is special
No, "panko" means "breadcrumbs." That's it, Rachel Ray. It's white bread torn into tiny pieces.
6. Anime is the pinnacle of Japanese artistic expression
Sorry, but it's not. It's also not real life. It is, however, a viable reason to learn Japanese. I have reversed my stance on this. Any reason to learn Japanese is a viable one.
7. Japanese game shows are crazy
They're not. They're not even game shows. What you see on YouTube are C-list celebrities being paid to do those wacky stunts. The shows like "Takeshi's Castle" have been off the air for decades.
8. Japanese TV is amazing
It's not, not any more. Clips of women having orgasms on TV and things like that are from 20 years ago. If you want crazy TV like that, go to Europe. If you want to see a chimp eat with chopsticks, watch Japanese TV.
Next time, to be fair, I'll tackle the misconceptions Japanese have about Westerners.