Adult Konohamaru.
Mindset: IC / Ready to battle
Location: The matrix "Construct" room
(No where to run, no where to Hide)
Starting Distance: 40 feet
Knowledge: Headcanon what you think they would know about each other
Win by KO/Death/BFR
Who Wins?
I would actually give this to Konohamaru. I think most people will go for Konan because she almost killed Obito and all that, but she needed so much preparation to do so. So she wouldn't be able to use the same Technique in this battle. Other then that Technique she doesn't really have a lot up her sleeve. Her arsenal is actually pretty small and there is not a lot of things she can do. Ya, she can make things out of paper, but that's about it.
Now looking at Konohamaru's arsenal. Oh boy.
Konohamaru's safest option would probably to just use Shadow Clones and Rasengans for a while. She can't really do a lot against a lot of Shadow Clones.
Konohamaru could also try to use his Sexy Technique against Konan to try and trick her or distract her like we saw Naruto do against Kaguya.
Konohamaru has a lot of Techniques we only see in the anime and I don't know if those count in this battle, But either way he still takes the cake.