Halo teman! I think this sentence is grammatically correct, and have a sense in English, even for a singular object; "kalian" is indeed a plural pronoun, but I think "hope" and "hopes" can be used here.
It is also easy to find sample texts using "hopes" in a sentence for a singular subject, for example:
"But you have hopes?"
"I have hopes."
Sherlock Holmes. The best stories by Sir Arthur Conan Doyle
And also here:
I have hopes - however slim right now in the wake of recent events - that they will be rendered irrelevant someday.
I hope it helps.
Selamat belajar! :)