You guys are amazing..! Nearly sorted already
hy-brasil is right, this is a half of a return post. And in the Sakura catalogue page, PC15 is "red". But also, PC13 says "crimson", also says "Return postcard", specifically on this list only. Others, I guess, are just single card, not folded. So, I am guessing this is more likely PC13..? (the value note: the price indication is for both parts are not separated, but one way was used)
Watermark has some numbers, which I am really puzzled, as they are 9 and 10 (or 7), in old writing. I am guessing that is 19, as year 1886 was Meiji 19.
This card was originally folded form, posted from Kyoto (Nishinotoin-cho / Shimogyo-ku in modern map) to Osaka (Tenmaji-cho / near current Minami Mori-cho). This beautiful hand writing was done by Mr. Yamada and recipient name I can't identify..

I recognise some characters, but no surname appeared on search. I wonder how postmen managed to deliver posts those days, without number of house, just saying "East turn from new bridge".
On the left hand frame, it says this is posted on 7 November.
The top left flowers are, yes, Chinese bellflower.

And melony heraldry is paulownia.
