Hey there, RetireJapan.
I've been lurking here on and off for a while, as well as doing a bit of reading (finished up Millionaire Teacher a few weeks ago) and want to start off investing.I'm in an alright spot, cost of living wise, and have been religiously tracking everything in YNAB for about 2 years now, just sitting on my savings.
My basic plan is to open an Interactive Brokers account, and use it to start purchasing something like a 85-15 split of index funds and bonds, funded by transfers either directly through JP Post Bank or Wise (whatever ends up being cheaper to do on a monthly basis.) It seems IB has removed their account minimum/10$ monthly charge for low-dollar amount accounts, so I should be fine on that front? It's not impossible for me to hit the 10k USD minimum they (used to?) require, but I'd much rather slowly add to my portfolio than dump it all in right away (especially given the current state of the yen.)
That being said, is there anything specific I need to really look out for using IB, in terms of not running afoul of the (terrifying sounding) PFIC regulations? Is there any specific things I should make sure to keep an eye out for when selecting index funds? I'm initially planning on looking into Vanguard for the low management fees, but I'm not sure if there's better options out there when you consider buying through IB/having to deal with currency conversions, all while making sure everything is on the up and up in terms of US laws. Any advice/anecdotes/things to keep an eye out for would be greatly appreciated! Thank you in advance.