I doubt it'll become a manga and hope it doesn't because I think he can write a better story.
Even though the species of Tree-Male x Female-Ghoul is unique, the ecchi-romcom future love with a relationship of holding each other's secret identity isn't original.
... I don't think the problem is that concept (because it's fairly common) but that the plots and themes revealed are very dull.
It seems extremely predictable.
By the end and throughout their progress, their relationship may be a cockblock tease of no sex and just stupid ecchi fan-service ... they may become an official couple or not but who knows if we'll see them date a lot or at all.
Their parents seem mature and open-minded so I don't imagine there being a conflict of species except against the humans but other than that...
There's just not much to it at all. Barely any potential from the execution. ... 3/10, if not lower.
I like the mangaka's art and character design though, so I hope he one day writes a good romance manga, or that A Story About My Girlfriend Whose Personality Changes Everyday gets serialized since its concept is very unique with good potential.