Of all the American chains I saw in Japan, 7-Eleven was perhaps the most surprising.
It turns out that 7-Eleven in the US is now just a subsidiary of Seven-Eleven Japan (part of Seven & I Holdings), after a Japanese franchisee of 7-Eleven took over the entire company in the early 90's Japanese bubble. If you look closely, you'll see the logo actually says "Seven & I" instead of 7-Eleven.
The US & Canada website (not intended for Quebecois!) only briefly mentions the relationship to the Japan.
According to Wikipedia, Japan has more 7-Elevens than anywhere else in the world.
Interestingly, my favorite convenience store in Japan--Lawson--was a store I didn't recognize, but it also had US origins (in Ohio). en.wikipedia.org/wiki/Lawson_(store)
We didn't end up getting any of these onigiri because we couldn't read the packaging (except for one that had katakana suggesting it had salmon). These mass produced onigiri are designed so that the seaweed isn't in contact with the rice until you open them.