Thanks for the recommendations, though I think I'll have a problem tracking those Japanese authors down in the UK.

I found Summer Of The Ubume by Kyogoku Natsuhiko on amazon in translation and the synopsis sounds great, but the price is a bit prohibitive at more than £550 (that's about ¥91438.00) There seems to be a 2005 film adaptation of it I found on YouTube, but in Japanese with Korean subtitles - I don't think I could follow that!

A couple of more recent J-horror films I have seen and really liked were Kiyoshi Kurosawa's Cure (1997 but released on Blu-ray 2018) and Before We Vanish (2017).

BTW, I have met and interviewed both Ramsey Campbell and Graham Masterton and they were both lovely, generous people. Which seems to be the case with horror writers, and also purveyors of extreme music. I love Extreme and Doom metal as well as Kawaii J-pop.... and one of my very favourite bands is Dir En Grey - whose visuals often qualify as horror - or anything involving 京 Kyo, it seems.

Cheers.