I’m not sure I trust Ms. Hisakawa. In volume two, she seems more concerned about the fact that she won’t be able to ‘use’ the girls anymore, than the fact that Kasumi just got eaten by a yellow knife and Kumi just turned into a borg, messing up Kumi’s life and changing her forever. In the anime and volume two, she also just watches when Kumi and Yuri are clearly suffering and crying emotionally because they can barely handle fighting the Yellow Knife on their own, instead of helping them. That was too intense for them to handle. Also in volume two, she gives Yuri’s Borg the ability to fuse with her, even though she knows Yuri doesn’t want too. In volume three, when the sunflower aliens trick Yuri, she gives up on Yuri and says she’ll never be able to go back to normal, so it would be better off if they killed her. Well, she was wrong and Kumi saved her. Kumi was more help than the teacher. And in Emulators she gets angry with Kasumi the Yellow Knife and wants to kill her too. I wonder if she cares more about the alien’s lives than the humans. Or maybe it’s her borg talking and not her.