~Anna~
"Hey look, it's Anna!" This is Anna, whom Kristoff has a bit of a crush on. They've hung out quite a few times, and he enjoys her company.
~Sven~
"Here's Sven!" This is Sven, Kristoff's trusty partner in the ice business. He is his best pal and they do almost everything together. There is no Sven without a Kristoff or a Kristoff without a Sven.
~Olaf~
"Have you seen Olaf? Oh, there he is!" Kristoff ignores Olaf most of the time, even though they are acquaintances. He finds him weird, but tolerates him.
~Elsa~
"Why, hello Elsa!" Kristoff does not know Elsa too well, but they are friends. Anna usually gets them together when the two of them have nothing to do, so they can know each other better.