Where does “支那通” come from?

支那通 (Japanese) comes from Japanese 支那, from Middle Chinese 支那, from Sanskrit चीन, from Old Chinese 秦 — {{w|Qin |State of Qin}}, {{w|Qin dynasty}}; Qin.

支那通 (Japanese): China expert or sinologue; China hand

Definitions

China expert or sinologue; China hand

Ancestry of “支那通”, step by step

支那通 traces back through two separate lines of ancestry.

via Japanese 支那

Step	Language	Word	Meaning
1	Japanese	支那	China
2	Middle Chinese	支那	—
3	Sanskrit	चीन	the Chinese people; China; a bandage for the...
4	Old Chinese	秦	{{w\|Qin \|State of Qin}}, {{w\|Qin dynasty}}; Qin

via Japanese 通

Step	Language	Word	Meaning
1	Japanese	通	authority, expert, connoisseur
2	Japanese	通る	to go through, to pass

Every word from Old Chinese 秦 →Every word from Sanskrit चीन →Every word from Middle Chinese 支那 →