Friends and AlliesEdit
Despite the fact they have just met, she always addresses him as Nii-sama, and seems to deeply love him, as she also did in the past. Her love for him seems to go beyond that of a typical brother and sister, straying away from normal sibling love, despite not being siblings in the present, such feelings were seen in their past memories, in which moments show them almost kissing. This in turn also shows that they were lovers. Satsuki proclaim that in this time, their love wouldn't be seen as a taboo, as once before. She also gets jealous whenever he is randomly kissed by Shizuno, or when he pushes his head on her breasts. Satsuki also seems to get easily flustered around them, heavily blushing when saying her promise was a kiss, shortly after he left the infirmary, although Shizuno ended up kissing Moroha instead, much to her dissatisfaction.
Shizuno is a classmate and friend as well a love rival of Satsuki. Due to their shared crush on Moroha, Satsuki is often frustrated by Moroha being the target of Shizuno's perverted antics, such as impulsively kissing him and placing his face on her larger breasts, all of which annoys Satsuki to no end.
The two girls tend to argue, with Shizuno always winning every single one even once insulting Satsuki's chest size before genuinely apologizing to the latter after noticing that she was very sensitive about the topic, as well as realizing that she had went too far in her remarks. This greatly irritated Satsuki as she saw that Shizuno possessed both the body figure and politeness in manners, both of which she lacked in.
Regardless of their rivalry for Moroha, both girls are shown to actually get along very well as Shizuno had asked to exchanged emails with her. Initially, Satsuki was put off by this strange offer but agreed and Shizuno became the second person that Satsuki has contacts with besides Moroha. The two even hung out at the mall to buy a gift for Moroha and got to know each other a little better.
They work very well together as a team, since Satsuki had joined Shizuno in battling the Metaphysical at the mall. Shizuno was even appreciative of Satsuki helping her battling Angela Johnson, as Satsuki was surprised at getting gratitude from her but accepted it with a smile.
Also, in spite of them technically being love rivals they are united when other girls show Moroha any signs of affection as shown with Elena Arshavina who had asked him out on a date and his comprising interactions with Angela in his time away.
They seem to be good friends.
Satsuki often argues with Leshya, especially when the latter calls Moroha, Ani. When they first met, Satsuki immediately disliked her, because Leshya voiced she was after Moroha. She often argued with her, usually resulting in her loss, similar to the way she loses to Shizuno. Satsuki is also jealous of Leshya because of her large breast size.
After Moroha managed to save Leshya from her hypnosis, Satsuki and Leshya often argued on who would be more fit to be Moroha's younger sister or lover. Satsuki wanted to be the only younger sister, even saying that Leshya could be Moroha's older sister. However, Leshya rejected the idea, stating she wanted to be the younger sister. These arguments usually lead to competitions between the two, which often go out of hand.