So that's why the Asian Games schedule was like that, since the Japanese professional basketball season opens on the 22nd.

It is generally common for ball sports to hold qualifiers for the Olympics or similar events in advance, but...
The reason the basketball finals for this Asian Games were scheduled as early as the day after the opening ceremony was... the B.League opening on the 22nd...
Maybe that's why the national team is filled with rookie-level players...
But even with the Asian Games being held in their own country, the league takes priority.
If it were Korea, they would have definitely coordinated the league to start after the Asian Games ended...