Behavioural/ personality data from health biomarkers

I'm working on a health tech project and trying to understand what's popular in Japan vs what we use in the West. The Japanese market seems way ahead in some areas but I can't find good info in English.

>What we're using in US/Europe:

Most companies here use basic wearable APIs:
- Terra/Vital/Rook - All pretty similar, just pipe raw health data (steps, heart rate, sleep hours)
- Fitbit/Garmin APIs - Direct integrations
- Recently found Sahha.ai which is different - creates behavioral profiles/personality insights from health data (like "active night owl" or "sedentary / early riser")

>Questions about Japan:

1. What are Japanese health apps using for backend? I see lots of cool apps like Lunaluна, FiNC, but can't figure out their tech stack.

2. Are there Japan-specific health APIs? Something from Rakuten Health or LINE Healthcare? Or do you use Western APIs?

3. How do Japanese users feel about behavioral profiling? In the West, Sahha's personality insights from health data are seen as either creepy or innovative. But Japan seems more open to personality typing (ABO / MBTI and all that).

>What I'm Really Curious About:

Also noticed Sahha partnered with Realize Innovations - are they known in Japan? First time seeing behavioral intelligence API in Japanese market.

Seeing how dead this board is I think this will be a total longshot on responses but I am happy to check in to see how this area develops and if there is a better place to post this. I looked at /psycho/ and saw how that was just a clusterfuck of MBTI.

what