I'm not sure how it happened, her memory was already gone when I talked with her. But... based on what she said, I think someone took her memories.

[Ishida is actually calm for once, even though he is still troubled by Mio's missing memories as well. It's bad enough that they have missing memories from their past lives, but now this...]

...Um, she forgot you. [How to say this delicately--] But she remembered liking a person named Satoshi. Do you know about him?

[So, not delicately at all. He's still working on that.]