the story's quite complete as is, dunno if they'll add more side story later on

I see, thanks, It's just that I've seen a recent negative review that said the game was "blatantly unfinished" and that it endend on a "To be continued screen", so I was worried for a second

I just finished the game yesterday. I would say the narrative is complete but it is purposely left open for additional content. The game story seems to coincide with the first two seasons of the anime. Arguably, I think the anime is the better telling of the story since they seem to skip some major plot elements in the game.