The guy being pestered by Aya is Kaede from "The Last Blade", a fighting game by SNK.

That means this is a MUGEN pairing.
Added tags for great justice.

MUGEN ftw

MUGEN: For all your random crossover pairing needs.

And the people who made it thought it was fighting game engine.

what?
are there any persons who thought it is figthing game?
really?
MUGEN is puzzle game.
if it is wrong, it is puppet play.

Magus said:
MUGEN: For all your random crossover pairing needs.

well said.
young people these days have no manners.
it is random, so we have to enjoy modestly.
I wish all uploaders dont forget to add "mugen_(game)" tag for people who blacklist it.

and please show me, more random and more logical crossovers.
and continue to make more beautiful stories.

sakuma said:
and please show me, more random and more logical crossovers.
and continue to make more beautiful stories.

Random and logical rarely go hand in hand.

I think the reason for this pairing is because the kanji "Kaede" means maple leaf, and Aya's fan is shaped like one.