Kakashi Hatake and Rin
Rin had a crush on Kakashi, much like Sakura has a crush on Sasuke. Rin, unlike Sakura, didn't
obsess over her crush and instead tried to help him whenever she could. Like when she gave him
the med kit for his Jounin promotion. She worried and cared a lot about him. Kakashi didn't really
seem to show he cared at all for her until the very end of Kakashi Gaiden. It is unknown what happened
between them after Kakashi Gaiden.
Obito Uchiha and Rin
Obito had a crush on Rin but Rin didn't seem to like him that way. She still cared about Obito
as a friend it seemed. Obito showed just how much he loved Rin in the end by abandoning their mission
in order to go and save her.
Minato Namikaze and Rin
The relationship between Rin and Minato is currently unknown because they didn't seem to interact
very much.