Overview
Saki is a loner type who prefers to do things on her own or in a small group consisting of people she trusts. She isn't social and is very stern, likely to scold others for stupidity or if they react hostily. After losing a cherished friend from the past, she can become clingy towards those she feels especially close to.
Arcana Heart
Heart Aino
Saki's childhood friend and the one she is closest to. She would do anything for Heart, and she gets envious if she believes someone else has gained her attention, although she isn't upfront with her feelings around Heart either. She's likely to insult her and can be cold at times, but deep down it's obvious it is only out of concern for her well-being.
Maori Kasuga
Her other good friend, whom she gets along with on mutual terms. Being wise and mature girls who are friends with Heart, they usually agree with each other. But sometimes Saki gets jealous when Heart responds more positively to Maori's motherly nature in comparison to her stern one. Saki has no harsh feelings for Maori though, and will jump to her aid in times of crisis.
Kamui Tokinomiya
Konoha
Lilica Felchenrow
Saki isn't shown to be particularly fond of Lilica.
Lieselotte Achenbach
Saki doesn't really like Lieselotte.
Yoriko Yasuzumi
Kira Daidouji
Fiona Mayfield
Saki befriended Fiona during her time in England when her father's career sent him there for a year. She cares deeply for Fiona, and losing her while in the Elemental World caused her a great deal of pain and made her become the antisocial type she is now. She desparately tries to help Fiona, and never wants to lose another friend.
Arcana Heart 2
Petra Johanna Lagerkvist
While they aren't shown interacting as often, they are able of holding a casual conversation easily.
Zenia Valov
Catherine Kyoubashi
Nazuna and Akane Inuwaka
Elsa La Conti
After a misshap during the Stamp event, Saki was quick to jump on Elsa and attack her, thinking she was trying to hurt or kidnap Maori. After realizing she had rushed to judgement she was quick to apologize. Since then they do not seem to hold any ill-will towards each other.
Clarice di Lanza
Saki is shown to worry over becoming like Clarice when she watched her interact with Elsa, and at times of concern she will make sure to remind herself to avoid acting clingy like she does.