Originally Posted by
nshizuka25
Have you tried putting your obaasan as your supplementary card holder? That might solve the problem?
Points for creative thinking, but I don't live in Japan, so I'm pretty sure my CC company would balk at that.
In the end, it turns out obaasan did actually have a valid & functional credit-card that she had never used (!), so she sent us a scan and I booked on her behalf. But
ChrisLi's suggestion of applying for a JMB account on her behalf, making the booking and then paying offline would have been our second choice. ^