Hey so uh, I am the original requester and those characters are from Kaitou Joker, it isn't a gender reverseal story at all.
It's just a cute picture of those two.
The one in the suit is a girl named Ai, the one with the blue hair his name is Spade and he has a tendancy to get fevers so she takes care of him as his friend and assistant!
If you look at them in canon Spade isn't so girly and Ai is a lot more feminine.
Infact she has an idol group with her sisters in canon called the Shuffle Sisters.