There is not an explanation and there will not be an explanation. There might be more stuff but explanations do not exist in this universe.

Also, I wrote a sick-ass continuation but it got lost to a combo strike of failing at captcha and going over the 8000 character limit, so I'll have to come up with something other than that thing (I will not rewrite).

Anyway, the reason Iri and Nae are doing this is for a bet, obviously. It's in the title.