Aki Hiyami/Relationships

Shinnosuke Tsuji
Hiyami is one of the only two girls Tsuji can converse comfortably with, although her guarded personality put him off at first. Since then, the two have grown close, with Hiyami being protective of him when their female schoolmates tease him. The two hang out together along with the other members of Ninomiya Unit on occasion, including a teammate's birthday. Hiyami addresses him by his surname followed by the honorific -kun, whereas he addresses her by her nickname.

Mirai Hatohara
Hatohara's advice was instrumental in allowing Hiyami to overcome her discomfort in social situations. Prior to her defection, the two used to hang out together and with their other teammates, including for their birthdays. Unlike Ninomiya, Hiyami does not appear to resent Hatohara for her defection and speaks about her with ease. She refers to the Sniper by her surname, with the addition of the honorific -senpai.

Masataka Ninomiya
Hiyami and Ninomiya are close enough to hang out together with their teammates outside of Border, including for a unit member's birthday. They do so often enough for Ninomiya to order a drink on her behalf.

Sumiharu Inukai
Hiyami and Inukai are close enough to hang out together with their teammates outside of Border, including for his birthday. She addresses him by his surname followed by the honorific -sempai, while he uses her nickname.

Kyōsuke Karasuma
Hiyami has a crush on Karasuma. His surprise at learning she is supposedly level-headed might imply that she has a tendency to get nervous around him. He refers to her by her surname, appending the honorific -san.