Regarding your graph. I’d like to believe that Ivermectin played a huge role in the case drops, but even the Japanese health authorities don’t officially acknowledge this.
I would like to believe so as well, but Japan has still not approved ivermectin for Covid. One wonders how many Japanese people are using ivermectin for Covid, considering this:
“A physician-led clinical study by Japan’s Kitasato University on ivermectin as a Covid-19 treatment is ongoing, but public broadcaster NHK reported on August 23 that it struggled to recruit participants.”
Link: https://factcheck.afp.com/http%253A%252F%252Fdoc.afp.com%252F9M48JR-1
It appears ivermectin may have some small effect, but measuring a small effect requires a large-scale study, and we do not have results of such a study yet.