I have an extension in my web browser that brings up an aerial photo from different parts of the world each time I open a new tab. A couple of days ago it was an image from Tokyo (I think), with a kind of sports field that I haven't seen before. I'm not able to find that image now, as the browser extension only remembers the last 10 or so images.
Here's how I remember it:
It could have been a soccer field, if the penalty area didn't have rounded corners. Also, I am unable to say anything about the dimensions of the field.
What sport is played here?