You have to do Lily's second quest and use her power on Ai in the afternoon first
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I've completed Lily's second mission, and also the school festival's maid cafe.
However, the Visor control scene is still missing. This is likely a bug caused by completing the school festival's maid cafe before finishing Lily's second mission.
The version is 0.8.9, all other characters except Eri are usable.
This game is really fun, thank you so much to the creator for their hard work.
It took me about two days to figure out the reason myself.
If you haven't used Lily energy control on AI no options will appear in Eri menu, meaning only Eri is unique.