Japan seems conservative compared to New Zealand, which limits immigration for those with a range of disabilities - including autism spectrum disorder:
https://www.immigration.govt.nz/new-zealand-visas/preparing-...
https://www.immigration.govt.nz/new-zealand-visas/preparing-...
I think that's a deliberate misinterpretation. It obviously means 'low functioning' autism rather than someone who's awkward in adulthood but otherwise leads a normal life.
Unless you qualify for asylum, then all bets are off and these rules are waived.