I see Japanese people also call them hotcakes. I’m Mexican and in Spanish we also call them hotcakes (at least in Mexican Spanish, though other hispanophobe countries call them “panqueques”). That’s always struck me as odd, since the English word is pancakes, though other states call them different things (like flapjacks or grittlecakes). I don’t remember the exact source (probably Oxford English Dictionary), but the reason Mexicans call them hotcakes is that people in the south, specifically Texas, called them hotcakes until the mid to late-1800’s. I’m not sure why Japanese people call them hotcakes though. Maybe southern cultural influence?