Texting with Japanese girls

hi! im texting with this Japanese girl I met during my trip to Japan, we spend all night at a club having fun and dancing, and when I came back to my country we kept texting thru instagram, but thing is that we don't talk as much as I would like to, she leaves me on seen for hours and sometimes during days, but the weird thing is that when she answers me is like she wants to keep the conversation flowing, sending me pics of what she's doing, and asking me questions back, so, my doubt is, is it normal to slow text in Japan, or is it just lack of interest.
and my other question is, should I do the same and slow down my messages, ask her why she does that or should I just stop sending her messages and see if she text me later.
thx!

btw, she has the one that approached me at first

Every person is different but I would say it's normal. Japanese people tend to have busy lives. If she's texting you I'm sure she has some interest to maintain this relationship with you but I doubt she thinks too seriously about it. After all you're a guy she met just one night and probably will never see again. You could try to stop sending messages. I bet she wouldn't make much effort to continue to keep in touch.