this is insanely romantic. i'm sold. like, i'm already a sucker for class S-inspired stories (marimite, anyone?) as well as the rose/candy yuri dynamic (rose being the older girl who's mature, reserved, probably has some kind of emotional baggage that closes her off, and candy being the younger girl who's naive and sincere). huge thank you to the scanlator, i'm bookmarking this one
I am more or less familiar with class S, but I hadn't heard of the rose/candy dynamic. That's a good label for part of the depth and nuance in their relationship. Kasumi is essentially a rose who plays at being a candy as a form of escapism while Haruyo is the opposite, a candy playing as a rose.
It ties really well into their underlying reasons behind seeking out this class S relationship. Haruyo is infantilized by being the youngest sibling and casually by the way her friends treat her and sought to become more mature, being in control and relied on by others was her fantasy when writing these letters. Kasumi is burdened by the death of her friend, and feels an acute lack of support, probably tied into her identity as the eldest sibling in her family. She seeks out the class S relationship because she wants a space where she doesn't have to be the strong/resilient person, she desperately needs a place to be openly weak and express all those emotions she's been bottling up.