I don't think it is correct, but my best guess was Hydrangea paniculata based on the opposite branching and leaf arrangement and somewhat close leaf shape. I kinda feel like I should know it...but honestly have no clue.
Well...it is something obscure...so why not an obscure maple? Agree...weird. Look like those might have been nicer apartments back in the day - maybe they hired somebody who liked diversity to plant some of the trees? Left over at a nursery that tried them out and didn't have any takers years ago so it was cheap? A (Japanese?) resident snuck it into the ground when it was tiny?