Omega Deuse--Well, that was the part that didn't make sense to me, so you've actually helped me out. Um, I guess she just yanked the pen off her hand and it actually tore the skin? But beyond that--the blonde girl is just a really random kid. Artistically talented mangaka, but flaky as hell.
More generally, I loved this manga all the way up to the point where that woman the blonde girl is living with showed up, and from that point on I have found it seriously frustrating.
(OK let's see--I've forgotten the names but if I'm going to rant I'll need them. OK, blond girl is Morishita, but her pen name is Sachi. Main character is Kawaguchi. The woman living with Morishita is apparently Takeda; I hate her.)
I really, really dislike Takeda. I hate her personality, I hate her self-righteousness, I hate the way she's worked hard to break the relationship between the two leads although it was none of her business, I hate the way they let her get away with her crap, I hate her condescending attitude which lets her be selfish while imagining she's all that, I hated her attitude towards Morishita back when she didn't realize she was Sachi, hated it while she was in denial, and still hate it now that she's starting to feel whatever twisted emotion counts as "like" for her. I dislike her so much that anything she might add to the plot, any tension and conflict she might introduce that should in theory make the manga more interesting, is just overwhelmed the moment she gets on a page by my fervent wish for her to go away and not be in my face. She is ruining this manga for me which I otherwise like a whole lot.
I want to see cute stuff with Morishita and Kawaguchi. I want to see Morishita hanging on Kawaguchi, and Kawaguchi slowly realizing her feelings for Morishita. I DON'T WANT to see that creepy little asshole Takeda.