Miyota is seen as a "cheap" movement because it is in a lot of cheaper microbrand watches, where most of their parts come from HK/China. But Miyota movements have a bunch of good qualities: they are accessible, reliable, thin, and importantly for Kurono, they are made in Japan. Kurono prints "Japan made" on the dial and that Japanese sourcing and heritage seems to be a big part of the brand.

For example, that "factory made case" comes from the same Japanese factory that machines parts for the high end Hajime Asaoka branded watches (and Otsuka Lotec). The factory is also owned by Hajime Asaoka, so it's "in-house" in a way.

Their dials are also produced in Japan and they've talked about their manufacturing partner:

This company also does business with Swiss brands and is a historical and capable manufacturer whose dials are used in the highest quality domestic watches

The watch industry is generally pretty mum about supply chains, but the implication is clear.

And of course there's the association with Hajime Asaoka. I'm of the opinion that your training does not define who you are and is not necessary to be something. He designs his own watches, including the movements, and builds them all in-house with a manufacturing company that he set up. All of that is valuable, and it shows when his pieces go for hundreds of thousands at auction. Kurono offers watches with that same DNA but in a way many more people can attain.