If you pay attention the mother disappeared..
Near the end a conversation between julissa and the twins..
It seems to me that the MC left the (path) they wanted and he ended up becoming a fighter by own choice..(and they are manipulating him from the beginning so that there is no other alternative)
In my view, Julissa wants to get her family together and have her father back, no matter the consequences (it's up to the player's choices to end her ambitions too)
I hope this VN continues, most of this genre is practically stopping..months for an update