With the new year comes renewed vigour to save money after some crazy overspending

I am finally looking to dive into iDeco, but I'm a bit confused by the eligibility. I've asked my employer about this a few times but it seems they're just as lost as I am.
When going through the eligibility questionnaire on the iDeco website, it asks:
Q3企業型確定拠出年金(企業型DC)に入っていますか。
The only pension I know I am enrolled in is the Shigaku Kyosai (PMAC) pension as I work in a private school. I'm not sure if this counts as a DC, which I think would make me ineligible for iDeco? If it is not, it says I can make 12,000 monthly contributions.
Is anyone else with a private school, paying into Shigaku Kyosai, and using iDeco?
Alternatively, is there anyone working in a private school, paying into Shigaku Kyosai, and part of a "corporate defined contribution (DC)" pension plan? Is that a separate from the PMAC (Shigakukyosai) pension?
I still don't know if I'll be retiring in Japan nor if I will be able to fulfil the 10 year requirement... Thinking maybe I can use my taxpaying years in Canada to count towards it if not.
I know I should have gotten started with iDeco years ago (got here 2020), but better late than never, I suppose! I realize I may not be able to access the benefits until 65, but I'm thinking the amount is pretty low, and the reduction to taxable income + tax-free withdrawal would actually still make it all worth it.
Thanks!