Question on Yahazu castle (Tsuyama)

I'm interested to visit Yahazu Ruins as shown on this video:
https://www.youtube.com/watch?v=nEtltaEJ1O0

There is very less information about this place, except for one reviewi in Japanese on Tripadvisor which didn't mention on the difficulties. Is there other resources on the hiking trail or reviews for this location?

Thank you.

There seem to be 2 ways to access. One from Mimasaka-Kawai (most sites list this way).
According to the following site, walking from Mimasaka-Kawai Station to the top and back takes 5 hours.

http://www.hb.pei.jp/shiro/mimasaka/yahazu-jyo/

This site says it's 2.4km to where the honmaru was located from Chiiwa Shrine (near Chiwa Station), and the author says it took him a little over 3 hours (1 hr 40 min to go up, 1 hour to go down).

http://castle.slowstandard.com/40chugoku/43okayama/post_1443.html

There are quite a few pictures. It doesn't seem like such a bad hike.

Thank you very much, Rabbityama!

http://www.tsuyamakan.jp/en/sight/index.html

Lots of info out there.