This chapter is a lot of fun and proves that Sabu is keenly aware of the fandom's impressions. She really is a master troll.
Still, I'm baffled at all of you saying Mei and Yuzu's relationship hasn't advanced at all, like, do all of you only count progress if they are having sex? Unlike citrus where Yuzu was the one moving heaven and hell to support Mei and Mei failed to reciprocate, citrus plus is all about Mei acknowledging her shortcomings and working her ass off to support Yuzu as much as she can. She's still a sheltered dumbass that takes things very literally but she's making progress and slowly understanding how to better express her own feelings towards Yuzu.
For me this has nothing to do with “progress” or the relationship between Mei and Yuzu “advancing” per se, but about the radical disconnect between Mei’s character as portrayed in the first series and how she is being depicted here.
In Citrus, once Mei and Yuzu were in a relationship, Mei was shown as being, within the confines of her repressed and hyper-responsible character, horny and in love. Her overwhelming sense of duty (to her family, to the school, etc.) prevented her from fully expressing her love and sexual desire, but both aspects certainly were there. (Yes, she objected to the presence of the hickeys after the fact, but seemed to be fully on board with the activity that led to their existence.)
Then once all the exterior blocks to the MC’s relationship were completely removed, Mei reverted to being considerably more repressed and skinship-avoidant than ever before. Her determination on returning home from her former fiancée’s was supposedly to restart the relationship from scratch, but in fact it has regressed far beyond any plausible new starting point.
Mei is supposed to be a person who is in love with and sexually attracted to Yuzu, but who is keeping those impulses in check in order to build the foundation for a solid and lasting relationship. But she comes off as someone who is only partially familiar with normal human behavior and whose previous experience with sexual desire has been permanently erased from her memory banks.