Kei Karuizawa/Relationships

Yōsuke Hirata
Since the beginning, she seems to have quickly established a relatively close and trusting relationship with Yōsuke. When the school first started, she was seen to have appreciated and supported his idea of having the students introduce themselves just before the ceremony.

After several days of school, to the eyes of schoolmates, they seemed to have form a strong bond as they are often seen together. In truth, they had just established and were just pretending to be in a relationship in order for Kei to not get bullied in school, so it is unknown how they really feel about each other.

Suzune Horikita
They don't have much interaction early on in the series and don't appear to be on good terms due to their contrasting personalities.

In episode 7, she was rather callous to her and told Yōsuke that they should leave so as to not spend more time than necessary.

During the survival test, after Yōsuke was chosen by Kei to watch over the boys in the class, Suzune stepped in. She didn't oppose Kei's request of watching the boys but requested that another boy join him on guard duty since he needed to be watched as well. After Kei mentioned that there was no other boy who seemed trustworthy, Suzune selected Kiyotaka.

In the novels, they still have limited interactions with one another but on one occasion, Kei saw Suzune and advised her to open up with Kiyotaka if she ever hopes to have a friendly relation with him. Adding on that if she continues putting him at a distance, she should then expect the same thing to happen to her. Hearing these unexpected words of wisdom from her, Suzune took them to heart and resolved herself to open up to Kiyotaka and get to know him better. Kei left soon after with her friends, being indifferent as to how Suzune would take her opinion.

Kiyotaka Ayanokōji
During the survival test, when Yōsuke was chosen to watch over the boys in the class, Suzune requested Kiyotaka join him on guard duty since he needed to be watched as well. While he was picked, Kei noted on him being invisible to the rest of the class, showing that she barely acknowledged his presence in their time together as classmates.

Due to his real thoughts being undisclosed multiple times, it is unknown what he really thinks of her.

Kikyō Kushida
Kei and Kikyō appears to be on good terms at least on the surface level. In episode 2, Kei went to Kikyō to borrow private points as she was out of it after blowing through her own funds and seemed desperate for points as she used their friendship as an excuse to do so however, it appears that Kikyō didn't go through with it.

Satsuki Shinohara
Satsuki is one of Kei's friends in Class 1-D. The two can often be seen interacting with each other in the anime and getting along very well.

During the survival test, Satsuki was among the many girls that comforted Kei after her underwear was stolen.

Maya Satō
Maya Satō is also one of Kei's close friends in Class 1-D, as they get along well. The two can often be seen interacting with each other in the anime and getting along very well.

During the survival test, Maya was among the many girls that comforted Kei after her underwear was stolen.

Chiaki Matsushita
Chiaki Matsushita is one of Kei's many friends in Class 1-D.