This game is a little difficult for me, so I never focus on getting the key. All I do is mess around with the AI lol. I'm playing the 2.0.1 build where Saiko has split personalities. I think she's really cute LMAO.
If you hear her say "Sorry", you can turn back around and have her follow you in her 'happy' mode where she won't desperately try to stab you (She literally just follows you harmlessly, gasps with her hands on her cheeks when you spot her and hugs you from behind which can lead to choking in some cases). She'll still stab you in one-stab intervals as you make a lot of progress, but that's only if you look directly at her. Just let her get away with stuff like stealing your keys and choking you out as well, since she'll still be in her 'happy' mode if you let her.