Seems like this might be a slow burn. Haruki and Himeko meeting again might be interesting, though I wasn't a fan of the vague way Hayato described her to his sister.
It seems strange it would be cheaper to use a coin machine to polish rice, rather than buy polished rice in the first place. But maybe there are a lot of supply routes for people to buy their rice as directly from the farmers as possible. But even so it seems to me the farmers would form a cooperative operating a facility just for it. It, again, would be produce cheaper results than an individual consumer using a coin machine to polish a very limited amount of rice at a time. Not living in a rice producing country, I must be missing some vital details in the whole scene, to justify such coin machines.