Well, Arantis IS a hard one to get. :) Try changing a little your conversations with him and see how he reacts. You could also use Haruka Nami’s detailed walkthrough of my game – you can find it here (https://harukanami.itch.io/second-chance).
I will try again! I did look for a walkthrough, though, but although I saw that she had written that she has made a walkthrough, I can't find it anywhere on the link you sent. Maybe I'm blind? D: Sorry for the inconvenience, but would it be possible to send me the link directly to it?