Upvote:2
You want to transit through the USA using a B2 visa. You are unlikely to have any problems.
If you already have a valid visitor (B) visa, you may be able to use it to transit the United States. If you are a citizen of a participating country, you may be able to transit the United States on the Visa Waiver Program.
https://travel.state.gov/content/travel/en/us-visas/other-visa-categories/transit.html
Upvote:5
What problems could there be regarding my situation?
You could be denied entry into the US. Since you already have a B visa, this is probably rather unlikely.
Are there any extra steps in me taking an international flight within the US as a foreigner?
Not really. The airline will report your departure to the US government, so you might have to show your US visa when you leave for Japan, but otherwise the process will be essentially the same as it is for a US citizen.