Naw, man, I'm with you.
Of course, Live-chan will continue getting older while Ghost-chan stays 16 forever. So eventually there will be a parting of ways as Live-chan graduates and moves on to relationships with real women in the real world.
However, I am picturing in my mind a comedy manga series in which Live-chan is now a 33-year-old Office Lady still carrying a major torch for Ghost-chan, and who has spent the past 15 years routinely concocting elaborate ruses to visit her old high school so she can be with Ghost-chan again.
Ghost-chan, on the other hand, is something of a player. While she is monogamous and faithful to whoever her current girlfriend happens to be, she does like the fact that they will eventually graduate and go away, leaving her the opportunity to be with someone new. And Live-chan has been cramping her style for the past 15 years, because Live-chan is jealous.
Ghost-chan also realizes that it's simply not healthy for Live-chan to still be this fixated on her 15 years after their breakup. So she is trying to help Live-chan move on.
Since this is a light-hearted comedy, there will be lots of zany RomCom shenanigans. Live-chan will finally move on after she hooks up with a teacher from the school. And a freak accident in the school's chemistry lab allows Ghost-chan to permanently reincorporate on the material plane as a full human once again, and she has a Happily Ever After with her current girlfriend.
It plays out great in my head I tell you what.