Maybe considered kosher for flexidox types but considering that the cooking vessel has not been kashered and the issue of a non-Jew starting the cooking. I wish things were simpler but they arent. Even if I wasn’t disgusted by the sight and taste of oden (theres a projectile vomiting story involved there) I would not eat combini oden.
At my last employer we had one Starbucks in the complex but 3 different combinis within a few minutes walk, two of which now have fresh coffee machines. Just as often though I’d simply go for whatever black was in the vending machine on our floor.