Sounds like you have a great opportunity to collaborate on technical details, etc.. but still have separate projects. More power to you!
Now if you got more specific and the other author happened to have beat you in a student council election then I'd say it's probably time to forgive and forget.
I remember just sitting there after helping the first spirit depart and thinking - wow. Which doesn't happen a lot in games, but the combination of the music, the storylines for each spirit and the time when I started playing (early in the pandemic) cemented the game in my mind as a piece of art.