Thanks for the chapter, TOOR.
Not that it's not regularly done for girls who look like Senko, but Konogi is trying hard to sell her. It'd help (not much at all, admittedly) if she didn't write the biggest hit to Senko's character that I've read so far (as of Henjo 128)--and it was a massive hit.
First, Natsuki's character was such that he didn't give a damn about anyone's opinions of him regarding his love for Eruko, and--accordingly--had zero interest in anyone aside from her, including Senko. He even said as much as the latter a chapter or two ago. Now, his character has taken a sharp 90°, resulting in its deterioration: all of a sudden, he's hyper-worried about Senko and his past feelings for her. Where'd his absolute confidence go? Where'd his single-minded laser focus on Eruko go? Exactly what reason did he have to forget Eruko and concern himself with someone patently inferior like Senko?
Second, Senko actually tried to play homewrecker between Eruko and Natsuki--despite being in a relationship and never having had any interest in the latter. She could have told Eruko anything else about Natsuki, but instead chose to tell her exactly what she knew--what anyone reasonable would know--would evoke jealousy in Eruko's heart. "Your man wanted me as soon as he entered school, but I didn't care, so I shot him down~" You can say whatever you like about how Senko is the "weird girl" who does and says "weird things" with no filter--there's only two explanations for what happened in this chapter: either she's cripplingly stupid, such that she can't understand the extremely predictable effects of actions that are sure to cause strife, or she's psychopathically callous--on top of being pettily spiteful as the one exception to that psychopathy.
And it was all just to sell the following line: "Everyone would be smitten with such a lovely girl!"
I remember there being a time when Konogi herself said that Eruko and Senko would never cross paths. I guess this is why--it evoked considerable idiocy in her writing, or perhaps revealed it: she wrote Senko as intentionally engineering a total lack of overlap between Eruko's and Takamura's schedules obviously because of Senko's insecurity before Eruko's superior looks and character; once she decided to ignore that plan, Konogi felt the need to not only sell Senko as equal to the heroine of her main manga's spinoff, but as superior.