One potential strategy to consider is waiting to sell the property until after you leave Japan, as this might exempt you from Japanese capital gains tax if you are no longer considered a resident for tax purposes.

Referrals may be a big part of your business so I'd recommend creating a business page here and having some of your customers write you a review.Lastly, one of the best ways for people to find you is through your profile.

Then you will have a 10ish min quick walk through the property and if his pictures matches the reality and you don't see anything abnormal, then after you sign with him assignment agreement and you put nonrefundable deposit and close in about whatever days you agreed on(usually up to 10).  

We run one note fund together and now he is running CWS, a much bigger fund for both accredited and non-accredited investors.

You did really well for yourself on this one.

One thing I'm struggling to grasp is scaling.

If you used conventional on the first one, FHA is still in your toolbox. 

One thing that I suggest is that you add Multifamily investment groups from Facebook to your list of sources for information and connections.

Any way to eliminate one or more of these manual steps?

Having a Realtor who knows about creative financing helps too in case they find one or hear about one from somewhere.