Despite the fact that this chapter focused on the main character of the story and her issues, Yatsude still shined the most. Fuck I love her, so cool.
Calling it right now: I bet Yatsude dated that gyaru girl but she, being stupid and all, did something bad to Yatsude (maybe she did not even see their relationship as real because they were both girls) which pissed Yatsude off big times. This is why she didn't want to go to the club and you could also use it to explain why she is trying to hook her friend up with Tsubaki.
Yatsude, stop being so fucking amazing, you are constantly stealing the spotlight.