I just found some good patterns if anyone was making a costume for Sailor Moon!
The first one, which is actually perfect for a Sailor Senshi uniform is for an ice skating costume. I don't have a link for the pattern because it is old but the number is Butterick 5781. Here is a picture
of a Sailor Mercury costume that I borrowed from a friend. She used this pattern! The collar she just made from scratch.
If you want an actual pattern for the collar I found it looking on the internet. It is a child's pattern but if you got the largest size avaliable then I think you would be ok. Mccall's 3759
I hope that helps anybody! Just thought that I'd pass that along. ^.^