Over the past year or two I have become pretty successful at cooking rice Japanese style, at home on the stove, as recommended by Keiichi-san in a post on the Tenkara-fisher forum.
( I think the key steps are: a) don’t use to much water, about 1:1 ratio, depending on type of rice , b) soak the rice for 30 - 60 minutes before cooking it)
However, the above video is intended to show how to cook rice in a mess kit or Hangou (ハンゴウ/ 飯盒). Good for when carrying your cooking kit.
But a hangou is thin metal. I think the rice actually cooks much better in a pot with thick metal bottom…
Steaming rice below a wood fire is an interesting method I was not familiar with.
Seems to be similar to the method shown in this video. Where she steams the rice in a plastic bag.
However, I think steaming the rice in a damp towel (tenugui / てぬぐい) in soft sand or gravel, below a stone, with wood fire on top - would be easier than in the hard ground as shown in this video. She certainly did not need many tools to cook her rice.
You mentioned using Miso Seasoning. If you like Miso (味噌) I found this interesting rice variation that would match well if you already have a wood fire going.
Miso Kiritanpo ( 味噌きりたんぽ )
To find other methods of making Miso Kiritanpo try doing an internet search for -
How to make Miso Kiritanpo or in Japanese - 味噌きりたんぽ 作り方 .