I should have finished that flip in early Sept '22, but we basically just started around then, and then in late Sept '22 Hurricane Ian came through. 

That gets worse as you get farther out of the cityTLDR: values depreciate, inflation has gone basically nowhere in Japan for a long time, the supply of housing is pretty good compared to demand (unlike the US) and that's because of flexibility with rezoning and development, taxes on rental income are high. 

So I'm basically trying to explore if i can borrow money in an alternative way than conventional loan.

It will familiarize you with the basic terminology and benefits.

Quote from @Erick Pena: A "good" rental property is one that covers all expenses (mortgage, taxes, insurance, maintenance, property management fees, and any other costs) and still leave a surplus (commonly referred to as cash flow).Calculate cash flow as: Cash Flow = Rental Income − Operating Expenses − DebtThere's much more to it, but that's the basic idea.

You understand some of the basic concepts, but also have some giant holes in your plan.

So far, I am just breaking into the industry with a single-family buy and hold  strategy that, from what I can tell is basically the BRRRR strategy.

Thats an important question to ask nowadays, we were scammed by a marketing/SEO company who is now overseas and has a PO box in US only so basically untouchable.

I'm curious on peoples go to approach to secure financing for an investment property - use a broker? start w local bank or CU ? or even a local brick and mortar bank?

It will familiarize you with the basic terminology and benefits.