The similarity with katakana ケ is coincidental. The small ヶ symbol, which, technically, is not a kanji, (probably) originated as a graphical abbreviation of the kanji 箇 (one of the two upper pieces). When the symbol is used in place of 箇 as a counter word, it is read as 「カ」. When appearing in a possessive role in place names, though, such as 袖ヶ浦, it is read as 「ガ」.I didn't know the ヶ in 「一ヶ月」is a small katakana け while it is pronounced or written as か.
I don't know if it is alright to go off the topic. Isn't 関ヶ原 is a name of place and so is a proper noun according to how English grammar classifies it?ヶ and ヵ are interchangeable ａｓ long as it is not a proper noun like 関ヶ原
@Lomaster wrote "as long as it is NOT a proper noun", meaning that proper nouns usually have one, fixed, standard way of being written.I'm not quite sure if ヶ and ヵ are really interchangeable in this sense unless 関ヶ原 can be alternatively written as 関ヵ原.
Bascially, yes. Incidentally, the modern Japanese possessive の was previously expressed as が in older forms of the Japanese language.Are you saying the ヶ read as 「ガ」here means "'s" in this context? So 袖ヶ浦 means 袖の浦?