Using USA powerstrip in Japan...

ok so say i am going to be out of town....and have this with me

The black adapter is Europe/USA. It will be useless in Japan. However, a good thing is that you can plug your US extension cord and US power strip directly into a wall outlet there. The voltage difference, 100V or 120V, is not important. You can use all US electrical appliances in Japan without a transformer.

Important: there are areas in Japan that utilize 200V mains. Most of US appliances have dual rating, from100 to 240V, but first you need to make sure that yours are, including the power strip!

I have had my T4i (usa) and Macbook (usa). The plugs im Japan outside from large hotels do not have the third ground plug. This was a slight problem for many of my friends with PC's that had cords with (usa) third ground prong. Easy fix and a local (Japan) electronic shop.
I have bought a Japanese 6D and don't have any fear with the battery charger. People buy 'grey marker' cameras and OEM chargers all the time.
I trust them over any off brand. - Living in Japan since March 2013

As for your ideas, I would not do it. Just leave the US power adapter at home, if it is a an issue with a specific device, take it to a large electronic shop, some speak english and the volt numbers are easy to see on the device without a conversation. They will understand what you need by experience.

Roll down to the Japan section on this site and you'll get a detailed answer on what works and what might not:

http://www.stayonline.​com …-international-plugs.aspx

On the same page, further links to plugs, cords and adapters specific to Japan should dispel any remaining doubts.

Enjoy your trip!

Related side note, the power strip you linked likely has an active recall. We had to pull a couple dozen out of service at work last year. Please be aware and stay safe.

http://www.cpsc.gov …lls-APC-Surge-Protectors/