I'm not exactly a fan of Mei - never been but I'm not particularly mad at her in this chapter. I felt it was a necessary turning point for both of them to "mature".
Up until now Yuzu had been floating in the clouds - so straightforward and in love. She's so into the moment it's unrealistic. On the other hand, Mei was just "pretending" to be mature. Now it will be interesting to see how they move on from here, I personally liked Yuzu's character development.
One way or another, even if the marriage was decided by Mei or their tradition, Udagawa-san can still back out if he feels like it (if he's the fiancé). I didn't think there's a possibility of Citrus going over them being high schoolers but now I kinda want to see how this would be laid out.
I feel sad for Yuzu nonetheless but it's a good chapter, thanks for the trans and scans. :)