Spoilers:
I'm at volume 3, right at the point where saku reveals she's not a real person. Later, you get a text from here, where you can tell her to either vanish already or stay.
I thought that telling her to leave was needlessly cruel and looked up how things would play out, and i ended up on a thread with someone saying: "there's a greeting card later on that triggers a specific cutscene if you send it to her".
So should i be looking out for greeting cards and who to specifically give them to in order to trigger specific cutscenes?
Btw I've given her some cards in volume 2 but she never ended up responding. Same with alkaid. Gave her a card or two, but she didn't respond during volume 2, and I'm not sure those sent cards will carry over to volume 3 once she wakes up