We tend to spread out across the sidewalks.
We get involved in talking with one another, gawking and tend to forget that other people need to get past us.
Sidewalks are narrow and can be very crowded.
That doesn't leave much room for the other people who are trying to walk there.
Remember: it's their home. We're just visitors. Let's not be ANNOYING visitors.

We drive on the right, so our tendency is to walk on the right side of sidewalks, stairs, etc.
Japanese drive on the right and GENERALLY stay to the left when walking.
Stay to the left and you won’t bump into as many people.

HOWEVER look for UP/DOWN arrows on stairways in stations (usually in kanji)
They'll tell you which side of the stairs (kaidan, remember?) to noru or oriru.
Not everyone will be paying attention to the signs, but WE will.

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