It's going to be a lighthearted story with serius arcs in between.
A clearly harem story centered for the MC (just to make it very clear).
Fast-paced, but won't exactly ruined the uniqueness of the original story; the more 'realistic' romance and great character with deep thoughts or whatever.
The MC is a OC (Original Character created by me), and he's not an NPC whether in that world or story sense.
I'm going to repeat it again that he's not an NPC (or like Supporting Character for more serious answer) because (VERY SPOILER) the start of the story will set it up like he's not attracting any women.