i found 'otokonoko' tag in the pixiv page, since the other image i assume are girl since they have breast and only harusame thats doesn't have breast so safely assume harusame in the picture is a boy

Translated.
Guess since he confirmed himself as a boy, I've added the crossdressing tag. Then that means, it's a cosplay of Harusame?
Or is it more like a gender bender?