The pictures are human girls but they are treated like real tanks. For example they don’t have a nurse, they have a mechanic.

I’m pretty sure this was the one… https://www.humblebundle.com/store/panzermadels-tank-dating-simulator

There was a visual novel game, probably over a decade ago… About a boy who went to “tank school” but ended up in a school of girls who were actually ww2 tanks. The funniest part is it was historically accurate to my knowledge. Like the American tank and German tank hated each other and the French tank kept crashing into things and had problems stopping.