Author's really trying to make this as soul-crushingly painful as possible, huh?
Fuyuki's being an idiot, deliberately risking her chance with Shiki out of some misguided notion that her friends will be happier with each other and that her own happiness doesn't matter (in real life, this is how you end up alone), but since she's on the cover and Sayuri's not, it's a foregone conclusion. Either Shiki will reject her, or even more cliched, won't hear her over the fireworks, leaving Fuyuki to swoop in guilt-free. All of this build-up is just proactively twisting the knife.
Firmly Team Sayuri, by the way. I will stay on this ship and drown when it sinks.