What is the meaning of this 'fox' hand gesture? In chapter 729 of トモちゃんは女の子 (Tomo-chan wa Onna no Ko), two characters are negotiating, while other two do the hand gestures depicted in the following image:



By the Giseigo (Onomatopoeia) used here (コンコン - Kon Kon) I deduce it has to do something with foxes (Foxes being described in Japanese folklore as  very intelligent and cunning). I have seen the same gesturing a couple of times before (I don't remember where) in the approximately same situation (a character leading another by the nose).

What is the meaning, then, of said gesturing? A reliable source or reference would be appreciated.
The origin of it's recent popularity is likely linked to the female metal band Baby Metal which popularized it, potentially as a variation (perhaps accidentally) of the Sign of the Horns (Maloik sign in Japanese). Often referred to in Japanese as キツネサイン or Fox sign. Associations to Shinto shrines and fox masks are present in some of their works, so it might have been capitalized later on as part of their brand.

In the given context, there is likely no deeper meaning besides a cute greeting between girls. Perhaps used like the Peace sign. The sign itself probably predates the band. As it's see used in various places including the WWE, as the "Too Sweet Sign". 

It probably not like one of those campaign that catch on via social media for promoting a specific purpose.

The gesture itself predates modern pop culture and can be see in Buddhism or Hinduism as mudras called the Apan or Simhamukha, depending on who you ask.