Just like how Moka reacted after hearing Ueno's confession, Chisaki acted surprisingly cool when Kanako revealed that she also took advantage of Ueno's sexual desires. Chisaki displayed zero signs of anger or jealously upon hearing this revelation. Instead, Chisaki showed compassion of her friend and tried to redirect Kanako's guilt so she can heal properly. I had some speculations that if the bully trio learned about their sexual relationship with Ueno, the revelation might splinter the group but after this chapter, I'm confident they'll stick together by series end. I bet once Kanako and Chisaki learned about Tsubomi's practice sessions with Ueno, they'll probably laugh at Tsubomi's efforts and help Tsubomi find a boyfriend so she can lose her virginity properly, lol.
As for Kanako, I'm pleased she properly confessed and I'm pleased that Chisaki rejected her properly instead of just apologizing for not returning Kanako's feelings. With Kanako accepting Chisaki's answer, Kanako can stop her self-destructive nature and have a healthier mind once again. With that said, I'm not sure what was Kanako's strategy of making Chisaki fall for her in the grand scheme of things. After they had the one-night stand together, Kanako told Chisaki that she will try harder to win Chisaki over.
But later on in the story, Kanako admitted that she never made a serious attempt in doing so...
Instead, Kanako continued her campaign of trying to control Ueno's desires until she hurt someone that she didn't want to hurt. Even if Kanako managed to get the results she wanted with Ueno, trying to win Chisaki's heart was a task she had little chance in succeeding...ah well....
At least with the confession, Chisaki might be more willing to move on from using Ueno as her sexual outlet. Seeing Moka and Kanako, her two friends, getting hurt because of her lust should sour her desire to continue bullying Ueno. We'll see once she finally talks to Ueno to settle things once and for all.