Judging by how the cosplayer is panting in fatigue, I can guess that reversing the costume takes quite a bit of effort.
Needless to say, that's some fine tailoring.
It's reversible and turns into an Osa-Reimu?HfffShw-shffShuffEndurance ChallengeChffHufff
PufffPantRsshThere's a secret to this costume?Good work, there...What kind?ShffShff-rssh