I dunno... if you stepped in the backroom of any of these bakeries as I have and watch them work or asked about the ingredients they use, you might feel differently. In general it is a lot of stuff that is not good for us, as most konbini food, and a lot of flavoring to mask the otherwise bad taste. Really... about the same as in the US. Maybe a bit less sugar. I'll take a good real bakery that makes real bread over any of it anyday. There is a guy near here who studied at a traditional bakery in NYC and cooks wonderful sourdough bread everyday from scratch. Not a common thing in Japan, but oh so good.
But anyway, apologies, I don't mean to be negative about your post. Even tho I know what is in them and am not a fan, I also get the donuts more often than I should. The chocolate ones, same as you. Sugar is too hard to resist sometimes ;)
RE: Donuts in Japan!