The first word promised in the overview article is totemo. Compare these two sentences (given in translation).

Both are natural modern Japanese. The first is close to “very,” the second to “by no means.” The same totemo is doing entirely different work.

How Shinmura Izuru saw it in 1940

In the chapters “Yama-kotoba” (“Mountain Talk”) and “Totemo hokō” (“Supplementary Notes on Totemo”) of Nihon no Kotoba (1940), Shinmura takes up this totemo. What drew his attention was the first usage — as in totemo omoshiroi, attached to a positive statement in the sense of “very.”

Shinmura’s observation was this. This way of speaking, he wrote, came out of the mountain talk of places like the Japan Alps in recent years, spread to the cities, and quickly caught on among the young generation. He and his fellow “old men” hardly used it, he says, and it sounded rather odd to their ears.

In other words, as of 1940, totemo omoshiroi was still a new, unfamiliar way of speaking. Before that, totemo was ordinarily used with a negative word, as in totemo … nai.

Why did it attach only to negation?

So what was the original totemo? Shinmura reasoned as follows.

Totemo was originally a shortened form of totemo kakutemo. Totemo kakutemo was a phrase meaning “whichever way,” “either way,” “in the end.” Even reduced to totemo, the meaning of “whichever way / in the end” remained.

That meaning goes very well with negation.

An expression whose sense was strongly negative — “no matter how, not…” — gradually settled in daily use into the form totemo + negation. As a result, it’s thought, the feeling that totemo means negation became the ordinary one.

totemo kakutemo whichever way / in the end shortened totemo whichever way fits negation totemo + negation totemo dekinai later totemo + positive "very" totemo omoshiroi (a new usage around 1940) Arranged by ToL from Shinmura Izuru's account
How the meaning of "totemo" shifted. Diagram: ToL

Still, there were positive uses

The story doesn’t end there, though. Shinmura found, on checking old texts, that totemo had also been used in positive contexts. In Noh and other plays, for example, there are totemo used in the sense of “anyway” or “in any case,” in positive as well as negative statements. In other words, totemo was not originally negation-only.

Rearranging Shinmura’s observations in time order, they run like this.

Shinmura was observing this last new usage as a fad. We check the detailed evidence by going back to the original in the close-reading article.

What is certain here, and what isn’t

What this article introduces is Shinmura Izuru’s view. That the etymology of totemo is a shortening of totemo kakutemo is something Shinmura himself states only tentatively, as “I think it was probably converted from the sense of ‘in the end, after all.’” And the route of the fad — “spread from mountain talk” — is something Shinmura passed on as a story he heard at the time, without being able to confirm it. How it is treated in present-day etymological research, we sort out in the verdict article.

Summary

PointDetail
ObservationIn 1940, Shinmura saw “totemo omoshiroi” as a new fad spread from mountain talk
Original meaningA shortening of “totemo kakutemo”: “whichever way,” “in the end”
Fit with negationUsed in “no matter how, not…” forms, so “totemo + negation” settled
Old usagesThere are examples in positive contexts too, in the sense of “anyhow”

In a nutshelltotemo was originally a word meaning “whichever way.” It settled into combination with negation, and later came to be used for positive “very” as well. Shinmura Izuru, in 1940, was watching that midway stage before his own eyes.