Only Arawi Keiichi or Ino could spend 16 pages on missing pencil lead... and make it actually funny!
Minor translation thing I ignored because it really doesn't affect the story, but as a bonus for anyone actually reading the comments...
A 'pencil' in Japanese is what Niacchi's using, an old style wooden thing. The japanese name is 'enpitsu', but they also just use 'pencil'.
What Koneko's using is a mechanical pencil, a 'sha-pupenshiru', i.e. 'sharp pencil'. Of course the Japanese abbreviate everything, so 'sha-pupenshiru' just gets reduced to 'sha-'. So she's asking Niacchi and Yukicchi for 'sha-shin' (mechanical pencil lead, which sounds like the word for picture, but it's not). What Yukicchi's using is called a 'seizupen', i.e. a 'drafting pen(cil)'. As seen here it usually uses finer lead.
So this is why Koneko calls Niacchi a 'pencilist', because to Koneko, what she's using is a 'sha-' and what Niacchi is using is an actual 'pencil'. And the BIG reason I ignored all this is that to be pedantic, every time Koneko talked about lead for her pencil here here she is saying 'mechanical pencil lead' and there ain't no room for that in these speech bubbles! 😹
Finally page 10 lower left panel, she's gone to Kansai accent, so we just used stilted language.