I don't know why but I think Mother Splats All planned this

Ah, the old classic cliche especially popular with the Japanese...

"They're fighting, so they much love each other".

What exactly does ケンカするほど何とやら means? They can't help but fight each other (and thus relate back to the fight = friend trope)?

Vezral said:

What exactly does ケンカするほど何とやら means? They can't help but fight each other (and thus relate back to the fight = friend trope)?

ケンカする = fighting, quarreling
ほど = extent, degree
何と = what, how
やら = indicates uncertainty
って = quotation particle
ね = confirmation particle

So literally it says something like, "That's their degree of fighting, is what people say, huh?"

Took me a couple of looks to realize that the girl sitting on the bench is not the N-Zap girl, but the daughter's friend from the first manga series (post #2354779).

Vezral said:

What exactly does ケンカするほど何とやら means? They can't help but fight each other (and thus relate back to the fight = friend trope)?

What she meant to say is the Japanese idiom "ケンカするほど仲が良い", equivalent to "A spat is the evidence they get along with each other". The phrase "何とやら" is corresponding to "you-know-what".

Brightlight said:

What she meant to say is the Japanese idiom "ケンカするほど仲が良い", equivalent to "A spat is the evidence they get along with each other". The phrase "何とやら" is corresponding to "you-know-what".

Ah, thanks. The online dictionary keeps pointing me at なんとなく which I interpret as 'somehow', which obviously isn't proper in this case here. I know of the original idiom after a few Google-fu but never thought they're related in this (the you-know-what thingy) way.