Rem
As Ram's last surviving family member, Ram cares greatly for her twin sister. Even as kids, Ram always encourage her whenever she felt inferior or depressed. When Rem died in one of Subaru's loops, Ram fell into a fury, adamantly chasing Subaru down for suspecting him of being involved with Rem's death. However, after Rem's existence is erased by the Authority of Gluttony, Ram completely forget about her sister and did not feel bothered by her falling into a coma.
Al
Ram has some kind of past with Al, as his normally carefree attitude changed when he learned that she was still alive, and he later expressed his disgust at the thought.
Roswaal L Mathers
Roswaal is the lord of the mansion where she works. According to Roswaal, both Ram and Rem are important to him, which is true as when Rem died, he blamed Subaru and quickly tried to kill him. Ram also stated that over time she developed feelings towards Roswaal.
Natsuki Subaru
Although they are friends, there are times when Ram is direct and sentimentally cold with Subaru, sometimes even getting mad at him. However, she is also willing to help him when he needs it, such as when they fought the Wolgarms or when she taught him how to write and read.
Emilia
Although Ram does not socialize much with Emilia, they have mutual respect towards each other.