Some members here are more familiar than I with the brand. Mariushi was more popular in some regions of the US and Canada, all but unheard of in others. I only started reading about them here other than a few tourers I spotted some 20 years ago,
They made bikes for some other companies, they manufactured themslves. A HUGE factory.
I saw not long ago a Road bike, Tange tubing. it was hi-end.
T-mar or somebody may ID the bike. The serial # should help. For now I would say that if it's Tange #2 or #1 it's certainly worth a look. In anycase try to find -out that much. Along with that, the crank etc. helps too.