I think the first step is to draw the leader's attention away from Saitou by making her switch targets from the soccer guy harassing her to Ichinose. They're only harassing her out of jealousy because they like the soccer guy who won't take no for an answer and keeps using public confessions to try to pressure her into saying yes after all.
The next step is probably sowing discord among the group since the leader is now into Ichinose and the two other bullies are still into the soccer guy, and Ichinose is acting interested, so they'll probably be jealous of the leader for having a real shot with a hot guy and abandon her.
And my guess is that the last step will be baiting Ichinose's fans to bully the leader out of jealousy by having Ichinose show very public displays of affection before leaving her in the dust. That or having Ichinose expose her as a bully by publicly dumping her saying something like "I didn't think you were that kind of girl." Even with no evidence, rumors will spread.
It's really petty and dumb. Even if Saitou
did go out with that soccer guy, those girls will likely still harass her because it wasn't them he was persistent in asking out. They don't really care whatever Saitou does, they just want whatever fuel they could grasp to throw hate at her because they're either frustrated in their own insecurities and wanted something to lash at, or they just can't admit they don't like her, or both.
With this, now that leader will become that object of envious hatred, and the best-case scenario would be that the whole group self-destructs from hating and hurting each other, and no one will want anything to do with them once their infamous reputation spreads through the school. Bonus points if they could get their destructive lashings out on instagram and tik tok.
