Not enough info to decide if you are really wasting your time Anodyne.
Interesting name, btw--your profession or wishful thinking for this forum?
I'm confused about a couple of things, you are from Tokyo but are there trying to make $$$? Tokyo is VERY expensive.
His not having a productive job is a concern. As for the rest, have you explicitly told him you are concerned where the relationship is going (or not)? I was with my husband for 5 years before we got married, in our late 20s (we were finishing school), so its not the time so much as the circumstances & general 'feel' as to the future of your relationship that you should consider.
Second thoughts can generally be amended with judicious action; injudicious actions can seldom be recovered with second thoughts.
--Cyteen by C.J.Cherryh