Seeing them hug at night reminded me of the ring-finger contamination scene. How the heck did her finger(?)'s sensor detect the ring as a contaminant, but not anything else (e.g. when hugging Takuma, or even cooking utensils)? I don't see how that can be coded, especially since the warning bypasses her own decision-making.
Also, it's surprising that her water-proofing only goes as deep as 2 metres. I thought it would be deeper.