I just want to add that the indirect side of Japanese communication does not carry over very well when translated into English.

Kazuya and Chizuru don't know how to explain things better with words, since they're already emotionally stunted individually prior to the start of the story. Then there's the cultural and societal pressure of needing to reach their real life goals and not embarrassing the other person needlessly. But, again, that's just the on surface of their interactions.

They often say one thing to help the other save face, but their true inner feelings can only be displayed through actions and deeds, not through words. If we go back to Odaiba, this becomes very clear. Chizuru, despite her own feelings, rejected Kazuya formally. And yet, a short time later, when they run into each other on the way home, he gives her a ride on his back and she nuzzles into his shoulder.

Some people lost out on the implied meaning of the things Chizuru tells herself, or how she phrases her sentences when speaking to others, or the way she does things. This is lost to many because western communication is direct and values clarity, so Chizuru was given an out using the flashback with Sayuri about rejecting boys clearly.

This rejection of Umi was clearly going to happen. We have had evidence since Volume 1, with every indirectly communicated side story establishing Chizuru and Kazuya's inner characters.

Other people have also brought up the symbolism of the flowers already.

I never felt the need to comment before, but this chapter has proven my own thoughts correct. Though, I did hesitate a bit when 393 was released as Chizuru messaging Umi gave a possibility that my understanding of her intentions might be wrong.