Yuya's not sure at first, what freezes him in place more--Zangetsu, or the potential of the Prince showing up. He's reluctant, for a moment, to go up.

"You can't hang here forever," he mutters, but it's also true that Gongenzaka is big, furry, and will be spotted and probably detained in an instant. And there's no option to go down, so Yuya reluctantly releases one hand on the ledge to hold it out for Zangetsu. Assistance up would be a lot faster.

Just don't eat it.