When I was 10 or so my cousins and I put a basketball hoop in the barn loft after all the hay bales were used for the season. My uncle came up the ladder and told us to be careful or we'd "get a bunch of coons in here playing ball." I didn't know that word was a slur at the time, so the image of a bunch of raccoons playing basketball was hilarious to me.
When I was in my 20's I told that story and everyone just grimaced. Someone had to tell me what he had actually meant.
See also story with drill instructor finding tremendous impact from the G-rated insult "boy," only to be spoken to one-on-one by one of his boot-camp charges to politely inform him why it landed so hard.
It's short for raccoon and a derogatory term for black people. As clever as it is to call this Sailor Coon to have a clear rhyme with Sailor Moon, I think it would be better for the name to have been Sailor Raccoon to keep the rhyme and ditch the brevity to avoid this association.