@princessusako cosplayed Dimande’s Neo-Queen Serenity dress (alternative) from Kodansha TV Picture Book Series: Vol. 20
Here’s her blog (Japanese) if you want to check out her other SM cosplays (every single senshi and then some). Her dedication is seriously unmatched.
Usako’s cosplays are seriously mind-boggling. You can always count on her to let under-appreciated characters have their time in the spotlight.