I don't think so. As per sat cost goes down, you can add a few sats on a specific polar orbit that covers that area perfectly. Japan uses that kind of polar orbit.
Are you talking about QZSS? That's a Tundra-style geosynchronous orbit, not a polar orbit. Such orbits are much too distant from Earth's surface for them to be usable with Starlink.
https://en.wikipedia.org/wiki/Tundra_orbit
https://en.wikipedia.org/wiki/Quasi-Zenith_Satellite_System