Inia Sestina

Inia Sestina is a Soviet TSF pilot. She prefers to hang around Cryska, whom she calls "sister", and often carries a teddy bear. Later on she befriends Yuuya and has become comfortable being around him, she even invites him to her bunker. Which nearly puts Yuuya in deep trouble with her superiors.

Like Cryska, it is implied that she may also have feelings for Yuuya, but it is unclear if she sees Yuuya as a big brother or something a bit deeper.