You would hope a country 9000 miles away has some cultural differences. While I've learned of a plethora since studying Japan in undergrad, I'm going to focus simply on what's stood out during the day-to-day.
- Things are Smaller: Our doorways in the guest house are around 5'8. Narrow sidewalks, alleyways by the dozens, compact houses, narrow gardens, parking spaces, stores, restaurants, roadways... space is used incredibly efficiently (this link is a fine example). Laundry is hanging everywhere, plants are hung and potted in clever nooks or guarding a narrow entrance. Cars slide in parking spots like a game of Tetris. It's charming, quaint, cute, cozy, but at times exacerbating. Walls are smaller/thinner too, so be quiet when you come home from the bar with... *ahem*
- Signs are Cute!: If you're going to order someone around in written form, or instruct someone to do the opposite of what they desire, why not making them feel all warm and snuggley inside so perhaps they're more likely to do it?! Exactly.
Doors closing - watch your hands!! 
Aww, look at his little hard hat for the construction zone!! =)
- Homeless?: A rare site. My colleague Dirk says the're whisked away out of sight so the city looks better; perhaps attached to the next difference...
- Cleanliness: Butt sprayers on toilets, wide public use of face masks, sinks open to all in grocery stores and restaurants in the middle of everything, trash sorted into 5 different categories and picked up 4 to 6 times a week - the worlds largest Metropolitan area looks great and keeps you feeling shiny.
These are our toilet controls in our guest house... no need to shower ever again!
Here's a sweet pic - a bag dispenser to prevent your umbrella from dripping!!!! Stick it in, pull it out...
- Bikes: They're all over the sidewalks. The road too, but people just do it on the sidewalks too - a lot - and I'm surprised there hasn't been an accident as an onlooker or victim.
- Driving: Left side.
- Service: Superb. The graciousness of any and all service individuals I've encountered in a all retail levels, at 7/11, a coffee shop, pub - whatever - they take your payment with both hands or in a little tray, hand it back to you that way, offer a bow, and seem to (at least from me, a foreigner) visibly appreciate kind words and a bow in return.
- Smoking: I recall the days of sections back home - now they're back. It doesn't matter. Pretty much the only place one can't smoke is on the sidewalk.
