I remember, very clearly, the first time I ever came across these, on that fateful first visit to Hakone in October 2002. MrLapLap and I had just met the day before, and as we waited (after the boat ride and as part of the Hakone Loop) for the bus to arrive, he popped into a combini and emerged with one of these. I was horrified.
Am happy to report that these double-carb items just don’t appeal to him in the way they used to. They became more and more disappointing as he matured and he hasn’t had one since LapGirl was born. Not to say he couldn’t be tempted, but I think it’s the benishouga that would be the irresistible enticement - the example in that picture is morosely lacking in red ginger.
As someone with a lifelong weakness for potato omelet sandwiches (and battered squid ring sandwiches) I am in no position to judge, but...

jib71 - I’m not sure the wiener bread dough would go with chorizo. The chorizo fat would melt, you’d have to get the cooking kind. MrLapLap suspects that chopped up olives would go with the mochi-mochi texture. Definitely works with bacon!

The last remnants after the morning’s demolishment