Tone is talking in an old kind of speech here. Can be translated as "What art thou doing?" in the 2nd frame but then I don't really know much about that way of words so, I put it as normal and noted it down here.
Hn?The truth is these girls' ball got caught up there....Chikuma, we are doing that!!What, it's just that?Ah! Nee-san.If you ever get into trouble, leave it to us!!Yes!! Nee-san!!He~y! Chikuma...!! What are you doing...?Thank you very much!!CombiGanationttai