Ahhhh i was camping and couldn't reply at the time, but basically:
Part of the reason isn't so much about Gojo, but more about how mc handles his arrogance. Also how she is almost as proud herself, yet doesn't show arrogance.
I also like his povs, its nice to get an insight on how he feels.
Now about him, I really like the way you did the pipeline between "this is a game to him. He probably believes there's nothing you can teach him" to respect and onwards, even going as "far" as thanking mc for teaching him.
The part where mc is explaining teleportation and asks for permission to touch him and he immediately goes "yes" and that by the end of the demo there's enough trust to just flick his forehead is a progress I enjoy.
Ah, and how he kinda stops being as arrogant as on the beginning, by the end of the demo is more like a friendly cockyness that somehow fits well w him fishing compliments from mc (Ok hes still arrogant, but it's softer)
Also how his sprite has his head hung high, it fits him. Also I really like his '^' sprite a lot!!
And lastly, this is more of an error, though its not too bad. If you click on "load" while playing and then press "esc" (without loading anything) to go back to the game, his sprite disappears.
And that's all. overall i like it a lot so far