Is This Chess Position Illegal? #3

An extremely simple puzzle, yet slightly offsetting. It will be a bit of a challenge for some to figure out how this position is either legal or illegal, but I bet someone will solve this conundrum. Just gotta figure out the correct sequence, because in chess, white goes first always, not black! So why has black taken the first move and not white? Figure it out!

"I find it quite fun to search a chess board to see if a certain position is legal or not. And by legal, I mean it is a something you can find in a normal game. Is this position able to happen in an actual game? In other words, is this position legal or illegal? Post your answer, and tell me what you think the answer is. Any and all chess variations accepted. If illegal, also tell me what is wrong with the position. I'll post the solution when someone answers correctly."