My generous interpretation of why Kobachi is feeling unsettled about Saraki practically getting together with senpai is that she's not necessarily in love with him and gotten hit with a wave of jealousy, it could have more to do with codependency. Saraki is a good friend of hers, probably the closest one, and if he gets a girlfriend, the time they spend together doing whatever will be cut short, and she will be effectively alone again. I mean, she cannot really get as close of a bond with her current "classmates" or with her other connections, and she was just lucky that someone as Saraki was effectively handed to her on a silver platter.
And the other thing is, her general realisation that she's stuck in the laboratory not really growing up, while the world around moves on.
At least I hope that's what this manga is going for, I would really hate it if she's made fall in love with him
And the other thing is, her general realisation that she's stuck in the laboratory not really growing up, while the world around moves on.
At least I hope that's what this manga is going for, I would really hate it if she's made fall in love with him