How would Japan even foster the manpower for a resurgent military with its current demographics?

• Shrinking/aging population (common to all industrialized countries)

• Clean diet of fish/rice/vegetables (and lack of toxic chemicals in cigarettes) gives Japan the highest life expectancy in the world, accelerating demographic aging/decline

• Cultural demarcation between "us" (日本人/和) and "them"/"outsiders" (外人) that leads to near-zero immigration

• Lack of large overseas Japanese diaspora, so there's not much migration to Japan in any way, shape, or form

This is even considering how advances in technology will gradually de-emphasize the manpower contingent of warfare. No matter how many drones there are or Axelspace satellite-borne lasers there are, Japan does not have the demographics to sustain an enlargement of SDF.

That's not to mention the overwhelming popular opposition to re-militarization in Japan. SEALDs might have been a fleeting movement, but it did tap into legitimate fear the Japanese public has towards becoming a military power again.