Mountain temples

Hi,
I have been to Japan twice, visited temples like Chusonji in Hiraizumi, Eiheji in Fukui, the Koya-san temple area and Hieizan.

I wish to go to Japan again and wondering, are there any more temples like this, like kind of secluded mountain areas temples like that? Well Chusonji maybe is not but it is a great place indeed.

Depends on your definition of remote. But Hasedera, Yamadera and Osorezan come to mind.

Shrines also?

Is mitaki dera (Hiroshima), Shokosan (Himeji), Kurama (Kurama, Kyoto) what you're finding.

You definition of secluded means:
Not popular (less crowds/people)
Hard to get to (not easily accessible)
standalone (away from the city)

Cause it does make a difference. E.g. Shokosan is accessible, but is not that popular. Kurama is standalone, and hard to get to but is reasonably popular among hikers. Mitakidera is known among locals but you won't find throve of tourists and may or may not be considered a hassle to get to. (It is away from Hiroshima central but there is a direct line from the station)

Kurama I wouldn't say is difficult to get to. The train station is right at the bottom of the hill to the temple. 47 services a day M-F at 20 minute intervals. Will take a little over one hour to travel to from Kyoto Station.

But it is not one of the more well know temples to foreign travelers. So at times you can have the place to yourself, especially M-F.

Here is a list of mountain temples in day trip distance from Tokyo
1) Nihonji at Nokogiriyama: Chiba
No English site

2) Musashi Mitake Jinjya at Mitakesan: Tokyo
English site is under constraction

3) Tensono Hiking course at Kencyoji temple: Kamakura
http://www.japan-guide.com/e/e3104.html

My best recommendation would be
Mitokusan Sanfutsuji in Tottori prefecture: no English site

This place looks impressive:
http://www.tottori-tour.jp/en/sightseeing/806/

Some that I can think of:

-Hagurosan in Tsuruoka (the Dewa Sanzan as a set are great temples that are pilgrimage temples popular for hikers)
Also in Tsuruoka, you can do a hike/walk to Dainichibo, Churenji, and Honmyoji temples. They all house sokushinbutsu (Buddhist mummies), so it's a bit of a pilgrimage itself. There is a fourth temple in Tsuruoka, as well, but it's not quite in the same area as these three
-Yamadera in Yamagata

-Muroji Temple in Uda, Nara Prefecture

-Seiganji Temple tends to be overshadowed by Nachi Shrine, but they're located on the same location. Hiking to it puts you on the Kumano Kaido pilgrimage trail.

-Tsubosaka-dera in southern Nara Prefecture

-Daigoji Temple (including Kami-Daigoji) in Kyoto

-Yoshimine-dera Temple in Kyoto

-Kannonshoji Temple in Shiga Prefecture

There are many mountain temples. If you also like shrines and castles (castle ruins), there are even more options.

33 kannnon Pilgrimage here in Saigoku=Kansai.

https://en.wikipedia.org/wiki/Saigoku_Kannon_Pilgrimage

Here are some mountain temples.
No 1 8 11 12 20 25 26 27 31 32 33

and Hiezan enryaku-ji though it is aside Kyoto.