So, I’ve been watching 化物語 and the name of one of the protagonists is 戦場ヶ原 - I did a bit of digging and it’s a place name in Japan. But, how does this name work? the small ケ confuses me. Can someone explain it?
It’s pronounced が, because it’s not actually a small ケ, but rather a simplication of the kanji 箇.
In the context of place names, the precise grammatical function is the same as the particle の.
ヶ in this context is an old-fashioned thing that works a bit like a の and sounds like a が, and ヶ原 specifically is a relatively common place-name ender.
The most famous example is probably 関ヶ原, as in The Battle of Sekigahara which capped the Sengoku period.
One other place you might notice it is the movie poster for Isle of Dogs (or would have, anyway, in 2018 when I learned about it…):
Incidentally, ヶ pronounced slightly differently, as か, can also be used for conveying amounts of time, most commonly months (I suppose because it differentiates them from the calendar months), as in 1ヶ月 is one month.
戦場ヶ原 sounds like a pretty intense and remarkable name for a character to have to me, but I don’t know that it’s necessarily outside the realm of possibility, since it certainly reads like a name (just primarily more of a place name than a person’s, to me anyway).
And in classical Japanese が was the possession particle. It remains frozen in expressions like 我が家 or 我が国.
It’s a marsh in Oku-Nikko - I tried to visit on my last trip, but access to it was closed, probably because of Typhoon Hagibis coming through the previous weekend.
As a family name, it’s not. Only a few of the Bakemonogatari characters’ names are.