Rui Osano/Relationships

Suwa Squad
The members of Suwa Squad have a good relationship and hang out together outside of Border duty. Osano speaks informally to her captain and does not refrain from taunting him if she is so inclined, although she still addresses him by his surname, while she uses nicknames for Daichi Tsutsumi and Hisato Sasamori, who in turn address her by her surname.

Reiji Kizaki
Like her teammates, Osano refers to Kizaki by his first name, which suggests familiarity. Nonetheless, she is respectful of him, protesting when Suwa referred to him with an unflattering moniker.

Shinji Fuyushima
Fuyushima and Osano occasionally play mahjong together. He is normally the best player among those who visit the room of Suwa Squad, but he becomes the worst when she joins in, presumably on account of his inability to defy high school girls.

Kirie Konami
Konami and Osano seem to know each other, since the lollipops that Osano is fond of come from a stash which Konami bought after being tricked into believing that they would increase her bust size, implying that Konami gave them to her.