Where does “三つの密” come from?

三つの密 (Japanese) comes from Japanese の, from Old Japanese の, from Middle Chinese 能 — talent, ability.

三つの密 (Japanese): the three 密s that should be avoided in order to avoid infection during the 2020 coronavirus pandemic, promoted by the Japanese government, translatable as "the three C's"

Definitions

the three 密s that should be avoided in order to avoid infection during the 2020 coronavirus pandemic, promoted by the Japanese government, translatable as "the three C's"

Ancestry of “三つの密”, step by step

三つの密 traces back through 3 separate lines of ancestry.

via Japanese の

Step	Language	Word	Meaning
1	Japanese	の	genitive case marker; nominative case marker in a...
2	Old Japanese	の	plain, field
3	Middle Chinese	能	talent, ability

via Japanese 密

Step	Language	Word	Meaning
1	Japanese	密	something without breaks or openings, something dense
2	Middle Chinese	密	—

via Japanese 三つ

Step	Language	Word	Meaning
1	Japanese	三つ	three things

Every word from Middle Chinese 能 →Every word from Old Japanese の →Every word from Japanese の →