Tips for handling the rain during vacation?

We are going to Tokyo, Osaka, Kyoto from 10/17-10/28. There is slight rain the forecast.

Any suggestions or tips on alternative things to do on rainy days?

I can't imagine walking in crowded areas bumping umbrellas. How do the locals deal with rain?!

My experience of it is that everyone just gets on with life and bumps umbrellas, sorry. Try to walk in underground passageways (e.g. the substantial area below Shinjuku) to avoid it if you can, but really I suggest buying an umbrella and not letting rain ruin your plans.

Buy an umbrella from a combini and carry on as usual. If there is heavy rain when you are in Osaka then the aquarium is very good.

i just tell you one word:
Onsen
:-)

Go photograph temples/shrines. You will have to hold umbrella in one hand and operate camera with the other. Rain adds extra mystic quality in my opinion to temples/shrines.

...and that's also how my first expensive camera got broken :-)

Watch out for Chinese carrying their umbrellas. Cos they ain't watching out for you.